I see vivalafai, you're talking about the AI detecting sneaking...
Does the AI properly detect invisible? (cast rain, cast that fire bursting thing around, etc...)
Taking damage from a condition while invis breaks invis (i.e. burning, poison). I don't feel as strongly about changing the invis skills as much as I do about making the AI better.
When you go into sneak, the AI doesn't try to look for you, so you can wait, reset cooldowns, heal yourself, fortify, go back into sneak, and basically restart the fight with full stats and AP, almost as if you had fleed, minus actually having to run back.
All the devs would have to do is make the AI look for you during their turn rather than just standing in place.
Also, I think flee should only be available in Honor Mode, and the Escapist talent should be scrapped. This is only my opinion.