When you create a spell or a magical item through Arcane Experimentation, do the results of experimentation (side effects, modified effects etc.) become part of the Lab text in such a way that anyone using it to recreate your work will incorporate them in the spell he learns or the magic item he enchants?
From a strict reading of the rules, it would not appear to be the case. The Lab Text simply provides a bonus to recreate the original effect; anything else, including the sigil of the Lab Text author, is erased. Otherwise, I could see a proliferation of Lab Texts with side benefits, which would probably shift the "baseline" for what's generally available to characters.
On the other hand, HoH:TL suggests that Lab Texts with side benefits resulting from experimentation - even of very common spells - are preferred material for Folios, which would make no sense if the side benefit in the Lab Text offered no advantages to the user.
Sure they should. A Lab Text is the formula that allows one to exactly reproduce what the original magus did, warts and all. This is also how I see magi passing on insights and breakthroughs without joining a mystery cult.
Well, not exactly. The sigil is explicitly changed, for example. And what would happen if the original researcher got the "exaggerated sigil" Modified Effect? Would the two sigils stack? What if people kept experimenting on the "modified" spell - would House Flambeau eventually put together a Pilum of Fire with 5 major benefits and 10 minor benefits?
This sigil is probably an outcome of the casting process as much as the learning process, since it comes with sponts too. I would imagine a spell with exaggerated sigil would exaggerate the caster's sigil.
Can you experiment when you're learning a spell using a Lab Text? I've never had it come up but I assume not. You're just learning someone else's spell.
Not really, you are reinventing the spell yourself, with help from the Lab Text.
No features can be changed. It's the equivalent of learning from a teacher, as far as I can see. If you don't exactly reproduce what's in the Lab Text you shouldn't get the learning bonus.
I never did understand why AM5 keeps emphasizing that you "invent" a spell ever time you learn it. The same phrase is used in the learning from teachers section. Perhaps someone involved with the game's development would like to chime in and explain why they see inventing as different from learning.
Magic is an ART, not science. Thats probably why.
I think it comes down to the mark each Mage leaves on his spells. This way you can't steal his mark by reading his texts.....
Also I think a more "Meta" reason might be the idea of making the PC's sigils more relevant in the game. If you adopted the sigil of the person who taught you the spell or wrote the lab notes you worked from many characters might not see much of their own sigils.
Not just the PC's, but every Mage. Sigils are really important in canon, to the point where we forget that. Messing with or trying to erase a sigil is like identity theft today, as far as I can tell.