Today I went ahead and did what I said I wasn't bound to do, and that was to use the Chanel Illusion D'Ombre Longwear Luminous Eyeshadow in Mirifique on my lashline. If you haven't read my review of it, go ahead and refresh your memory.
Grabbing my Bobbi Brown Ultra Fine Eyeliner Brush (which I'm most used to using for gel formulas), I attempted to tightline with Mirifique. I know my technique isn't perfect and this formula being much harder to control than the cake eyeliner I'm more used to tightlining with, I ended up with a much thicker line than I'd hoped. This simply means I extended further above the lashline, which is fine. After I'd done the right eye, I proceeded to work on the left, thinking that I could cleanup afterward if I wanted to thin the line a bit. The left eye however ended in disaster as I wound up with some irritation from the fallout. I had to remove and reinsert my contact lens twice over before being satisfied that most of the irritants had been removed.
What did I learn from this experience? If you wanted to, you can use it on the lashline and it can be done without irritation to the eye. But (pause), there's a 50/50 chance that little tiny bits will land into your eye and it's more trouble than it's worth. I think it's key to apply Mirifique correctly the first time as it does not lend itself well to application and subsequent cleanup. It leaves a trail of glitter. Granted there are a number of ways to clean off glitter, that means an extra step that personally, I'd rather not deal with.
I love the soft texture of the eyeshadow but wish that they didn't infuse it with all that glitter. I only really use Mirifique as a liner and I'd say stick to using it above the lashline if you can. It stays put even when used on the lashline though. The longevity of the product is impressive, without question.