Honestly this would be viable but there are some problems to it,considering its a just a little bit time consuming to farm current r8 mats for perfect elements and also their price tag in general.
Lets say we buy a ton of christmas stockings for 2 ec (instead of 3ec)damascence ores cost about 18-20 ec and radiance crystals cost 100.Those can all be exhanged for 2-20 perfect elements depending on how much you have.
Im kind of tired so my math might not be the best atm but id say less christmas stockings should be needed for it.Though id like to add a slight adjustment to ur proposition and say that it shouldnt be christmas stockings for rerolls but rather implementing christmas stockings into the perfect element exchange system.
Im not really opposed to this so +1 from me if done right