With the release of the Chalice of Opulence (and actually the oven from last year's Dawning), we've seen that Bungie can create an item that goes into your pursuits without the "ingredients" taking up spaces from your consumables. Why not implement this change to the mote synthesizer?
It would clear up so much space (1 slot for each stack of synth, with a minimum of 4) in our consumables inventory. The problem couldn't have been more prominent last season when they decided to release yet another two more consumables - the now retired Iron Burden and Wolf's Favor along with the four types of synths.
So yeah TL;DR - make synths part of the mote synthesizer the way runes go in the chalice.