I genuinely don't know what "rare drops" are anymore, really, so, just curious about it. I'd consider things like the demimaterias, but, not even sure those are still used in crafting later stuff? Naturally, if it saves you some time/effort on some hard to get materials, that's great. I myself haven't been too worried about getting desynth much beyond ARR levels, since most items gained out of it beyond that just seemed like stuff I could get just as easily by other means.