I beleive so...the new range/duration would have been part of the insite you gained. You can then create 1 effect to gain breakthrough points per insight. 1 insight per "artifact" you have to study
once you've finished the breakthrough it's been integrated with hermetic theory and anyone can learn it.
If your asking about effects you have created while working towards that breakthrough (but not done yet) I beleive others can learn the effects you have stabilized but they can not moddify them or creat their own.
And on a final note. It takes at least 1 season of study to gain an insight from which you can create an effect for breakthrough points. That effect is then made with experimentation and then must be stabilized.
So assuming all goes VERY smoothly (you find an artifact in 1 season, you roll a discovery in 1 season of work, you never fail to stabilize the discovery) It will take a minimum of 1 year to gain any breakthrough points. Assuming a modest effect level of 20 (will give 4 points (1/magnitutde)) it will take ~8-15 uninterupted years to create a breakthrough.
There is a fine line to walk here. You want to allow the character/player to have some benefits of all the work of finding, investigating, integrating, stabilizing, etc. Without giving him so much of a benefit that he decides he's gotten everything he wants and walks away.
I would suggest not allowing the character to create a spell or device utilizing the Breakthrough until he has accumulated several points. You'll see in the other chapters that the authors proposed sample partial Breakthroughs that allow something beyond the scope of Hermetic magic, but aren't so good that the player will stop trying to complete his research.
For an example from my chapter, Unlimited Range allows spells to be cast without an Arcane Connection if the character has +2 sympathetic connections. As a midpoint, characters are allowed to create spells that get close to this effect but require +5 sympathetic connections. As the character gets closer to the final Breakthrough the number of sympathetic connections are gradually reduced until they get down to 2.
Another way of achieving this progression for Ranges, Durations and Targets might be to increase the magnitude of the spell created by x1.5 or 2 and allow the character to eventually work toward the final. For example, Rune Duration adds 3 to the magnitude of the spell. A character might be able to use it at the half-way point of Integration, but it would add +6 to the magnitude of any spell he creates. Or instead of the duration lasting as long as the rune carving lasts, it might last for several years, but not indefinitely. Both allow a breaking of a Hermetic limit, but not so much that the player is going to say, OK, this is good enough, I'm on to my next project.
I'm sure you can come up with suitable partial Integration effects, if not others might be able to chime in with ideas.
And as for other's learning it and looking at the free PDF, you need to create (I think that includes studying another's spell) a spell with the Minor Breakthrough to be able to use it in any of your magic from then on.
Major and Hermetic Breakthroughs have to be taught as normal, and your research points are converted into a skill to facilitate this.
Virtues require Initiation, as with Mystery Virtues.
It requires another Breakthrough to fully intergrate these Breakthroughs so that anybody can use the effect if they have a Lab Text of it.
I agree, and I also took very positive note on your suggestion on the partial Insights and the Unlimited Range. In our saga I'll try for something similar with whatever Secrets the magi PCs will attampt to unearth.
Rune Magic can be learned by anyone who can learn Arcane Abilities. It's like Magic Theory; it's knowledge of what the different runes are supposed to do and how rune spells are phrased and crafted. If you know Rune Magic, you can make a guess as to what a given set of runes is supposed to do, though you can't be sure exactly what it's doing unless you investigate it in the lab. Knowing Rune Magic doesn't mean you can do anything magical with it, though, unless you're a magus who has made the breakthrough, just like knowing Magic Theory doesn't mean a scribe can make magic items.