Thinking about the early Order, when Hermetic Magic was still rougly formed and not yet as formal as we know it now...
What if you alwys had to Experiment? What if, in those early days, magi had to use Experimentation with every proceedure? From spells to enchantments, even Familiars and Longevity. What if?
The idea is that, "modern" Hermetic Magic and all the bells and whistles is the result of this era of random discovery. Then latter refinement put the results into a formal useable system. Safty proceedures and regulators were developed. Perhaps the "Risk Factor" is evolved from refraining to use what the old guys used to call a "Safety Factor" (lower your lab total and risk by up to three points).
What would Lab Texts from the Unrefined era look like? And what if one were to utilize them? Experimenting being a requirement for use of course.
Required experimentation when using a Lab Text? That's harsh! (And it means that you can't blaze safe paths for others to follow.)
If you can't even teach spells, or use a lab text, without experimentation...It means you're going to have a lot of warped spells (and re-warped spells as they accumulate side effects from passage down the line until someone goes ahead and reinvents a standard version).* The Diedne of the era will probably focus even less on learning spells - a Diedne with no spells at all will not be unusual. Lab Texts from this era might contain chain modifications so severe that they barely look like the core spell at all - modern Hermetic magi creating such spells in a stable form might well end up with a partially non-Hermetic effect, or an Insight into a Breakthrough. Magi will probably have smaller libraries just because experimentation occasionally hoses up.
You'd want a rule that governs how something that requires experimentation improves to the point of no longer needing experimentation.
Spontaneous Magic would gain a bit of relative improvement, since it doesn't require experimentation. Not enough to matter, perhaps.
It might be interesting to give each House an aspect of magic that doesn't require experimentation. So Flambeau never requires experimentation with Ignem, Veridius with enchanted items, Bjornaer with Animal, etc.
One thing that I have noticed is that the old, canonical spells often have little quirks, side effects and disadvantages, whereas the spells that players create tend to be 'clean'. I don't think the current experimentation rules are all that good, but I would love to see a different set of rules that makes it very difficult to create those 'clean' spells. You want to soak damage like a bear? In theory, that's a straight MuCo, but good luck getting a version of the spell that doesn't give you some bearlike quirk you don't want. Try to avoid this through lack of metaphor? The GM or Troupe will happily come up with something appropriate.