I suppose now is a decent time to ask how much are the mats needed for the "Perfect" items are going for on the MBs right now. Since they are gated behind desynthing the aged pieces they might be worth a lot.
With that said, I wished they at least added Whorl/Levin/Frost Demimateria.
On topic, I think SE is trying to make Crafting items mutually exclusive, Forcing players to choose which to specialize in and which to max out desynthesis levels as a way of controlling the markets, so as it stands it is as unlikely as allowing players to hold more then 3 "Soul of the [Displine of the Hand]" items at once