Slap in a Magguts +2 extender kit, which adds a barely noticeable1/8" in length, and you've got a non-top heavy 14+1. A lot less costly, and demonstrably better, upgrade for the P365X/XL (and even the 'regular' P365). If the rail can't be used for a light, why bother with the Icarus grip?
Don't think they can make the aluminum snap, because it's not flexible like plastic. Would make it hard to impossible to remove. I hear ya on that snap though. Makes you feel all warm and fuzzy.
LAG, McKinetec, Black Label, etc. OR you can pretty much use any XL holster cut for a threaded barrel and simply reheat the muzzle end. That’s what I did for mine.