It’s just impossible to avoid throwing away procs, FoF will guaranteed proc in the middle of a flurry cast and be wasted unless you want to throw away cast time on an extra frostbolt.
Course the one extra lance crit will do zero to fix frost mage damage and issues atm but this hole in the rotation still ends up a thorn in the side that just builds to full blown annoying sometimes.
Or if a FoF lance is what consumes winter’s chill have it give you a buff that makes your next FoF proc do extra damage. I would’ve suggested making winters chill boost damage if consumed by FoF but that only introduces a new tunnel gameplay issue of hoarding procs until you cast flurry for no reason.