I can't speak for Tellus specifically, but in the past when it's come up I think people have had two key problems with it:
It requires a virtue to do, whereas people had previously assumed that it was something that any magus could do automatically.
Developing a bonus to the point where it can be used by other magi is a long and involved process, arguably for relatively little gain. A lot of it can be done whilst you're doing other things, which softens the blow a bit, but it does tend to lead to the suspicion that the vast majority of Shape and Material bonuses in the Order have been created by White Swans in the Order of the Green Cockeral trying to progress to the next degree rather than people doing Vulgar Alchemy for its own sake.
I very much agree with @Salutor's two points, and get very curious about @Tellus's words «as written», which seems to imply that it could be mended.
I have always read the published bonuses as mere examples, and by the principles of magic, It seems to me that the shape and materials bonus applies whether or not the magus know about them,. He could discover a bonus, but he cannot invent it, because it was always there.
A Pralician's Comprehend Magic Ability can reveal some basic information about enchanted items and can multiply their Magic Theory for an actual in lab investigation.
the ruleset really is quite strange, but more relevant to the topic at hand it establishes the point that Shape & Material bonuses are not limited to the list of things in canon and that if you want more to exist you should feel free to make them up.
I assume that the primary reason for something not being covered in the canon material is that it has not been relevant to the authors of the various splatbooks and that the core book was limited to 1 page's worth of bonuses. In other words for purely out-of game reasons.
you want a statue to have a +4 bonus towards investing effects that animate said statue? Bam that's a totally fair bonus.
You want a bonus that improves an item but you want your players to not know about it with a Magic theory roll? Some magus came up with that bonus recently and the player characters have not heard about it yet.
That being said I do agree with previous posters that Vulgar alchemy is weird in the sense that the virtue kind of suggests that Vulgar alchemy is the way in which new S&M bonuses come about. In the past i chose to view it as an example of an in-game mechanic that was added to provide concrete guidelines for players to come up with new S&M bonuses rather than as attempt to exclude the process from hermetic magic. I have not analyzed its numbers sufficiently to comment upon how well it was designed.
You could choose to fully integrate Vulgar Alchemy into Hermetic Theory and then add a virtue that reduces the integration time to the list of alchemy mystery virtues, I suppose.
Adding S/M bonuses also messes with the Blending with Substance part of Inscription on the Soul, doesn't it, by changing the enchantment level required to blend a particular substance?
Another thing that occurred to me, which I may as well ask here as it's still related I guess, is that I was surprised not to see any mystical/legendary things in the shape and material bonuses - I mean like, dragon scale, phoenix feather, basilisk tooth, unicorn horn etc. Seems like the kind of thing wizards would traditionally seek out (yes they might do so for an arcane connection or vis, but still). Is there a reason for such things being omitted?
Both of these.
But what further sticks in my craw, is that the size of the bonus you "discover" isn't really related to how relevant the object is, just to the size of your numbers. Yes, I know there's supposed to be a sort of "appropriate-ness modifier", but if you're good at this trick, you can practically define something to be of strong benefit in a specific kind of magic. Which bothers me.
From some of the books not included in the PDF. Maybe somebody can update it?
Magi of Hermes, page 102
Battle Standard +2 leadership (?)
Magi of Hermes, page 103
Loom +2 Imaginem
Loom +4 weave cloth
Covenants, page 82
Aetites +5 fertility
Mythic Locations, page 71
Arsenic +8 magic that kills directly, without intermediate media
Arsenic +4 preservation of dead things from decay
Arsenic +2 stimulating the ill
Legends of Hermes, page 125
Agate +3 Auram (may be a typo that should have been "air"?)
Griffon's Nest of Gold +7 defense of home
Griffon's Nest of Gold +7 protection of treasure
Against the Dark, page 33
Flint +9 causing paralysis
Flint +6 protection from faeries
Flint +3 Ignem
Against the Dark, page 131
Black Hawthorn +7 protection from vampires
Black Hawthorn +4 protection from evil
Black Hawthorn +4 prevent disease
Between Sand & Sea, page 62
Asafoetidia +3 protect against evil spirits
Between Sand & Sea, page 73
Cypress (same as HoH:MC)
Lands of the Nile, page 89
Kassalan Dust +3 against the dead
Faith & Flame, page 123
Salt +5 preservation
Salt +3 protection from evil spirits and demons
Faith & Flame, page 125
Purple (murex) dye +10 royalty
Purple (murex) dye +7 rulership and authority
Purple (murex) dye +5 control people
Crimson (kermes) dye +7 violence
Crimson (kermes) dye +4 courage and martyrdom
Crimson (kermes) dye +3 sin
Lavender +3 cleansing / purification or healing
Lavender +5 protection from evil spirits
The Sundered Eagle, page 45
Porphyry +10 royalty
Porphyry +7 rulership and authority
Porphyry +5 control people
The Sundered Eagle, page 56
Magnes Stone, male +7 control iron
Magnes Stone, male +3 divination
Magnes Stone, female +3 purification
Magnes Stone, female +2 invisibility
I never went through and did the math, but I was under the impression that Vulgar alchemy allowed you to use new bonuses more quickly than standard hermetic breakthrough research. a pathetic virtue, even if that is the case, but not exactly worthless...
I assume that a new material or shape bonus would be a minor breakthrough, which means 30 breakthrough points over multiple seasons- even if you reduced the breakthrough points it couldn't be used in a single season like the virtue allows...if you decide that a shape or material bonus only needs a number of breakthrough points equal to the total bonuses, you still have to spend at least 2 seasons on the project, and accumulate warping...
OTOH, given the number of things S&M bonuses affect it seems you should be able to deduce them from a magic lore roll...
It should be way less. IIRC converting hermetic magic from using Latin to another language is a 15. Coming up with a Shape and Material bonus should be even easier.
Is there any chance you would be willing to share the rules for the integrated and simplified version of vulgar alchemy that your saga uses, to inform the discussion in this thread?
During any seasonal activity which uses Shape and Material bonuses (enchanting items, potent spells) a maga can develop a new Shape & Material bonus.
The troupe will determine the maximum bonus a Shape or Material can provide and players must track what Shapes and Material Bonuses they have developed.
During a season, a maga can learn to incorporate up to her (Magic Lore / 3) of that bonus. Thus, after one season of work, a maga with Magic Lore 6 could develop a new Shape or Material bonus of +2. In a second season, if the Shape or Material had a higher maximum bonus, that same maga could develop a Shape or Material bonus of +4. During lab activities over multiple season, the maga can only use the bonus learned from their first season (the lowest bonus).
Once the maximum bonus is developed by a maga, she can share that knowledge with others. By writing a tractatus on Magic Theory or Magic Lore, a maga can include the knowledge of one Shape or Material bonus. In a Summae, the maga can include knowledge of (2 x {Magic Lore / 3}) Shape or Material bonuses. A labtext can include knowledge of all the S&M bonuses used in the project."
We've only recently added it, so we haven't illuminated any situations where it might be broken yet.
In our saga we have been able to investigate objects and effects outside magi laboratories by using some variant of Opening the Intangible Tunnel.
The spell variant must be kept active or renewed for the entire timespan of the investigation, and the Intellego Vim lab total is capped by the level allowed by Intangible Tunnel variant.
Maybe it's not fully canonical, but it suits our style of play.