I've done a quick search for this subject but it hasn't been discussed in at least a year so here goes.

G4 Carbonized Matter is too obscure to obtain. I'm *not* saying that it's difficult to get, because it's a simple gather from lvl50 nodes, *but* it only appears at set times & in Mor Dhona. On the other hand, G5 Carbonized Matter is spattered all over Heavensward nodes & can be obtained from NPCs by exchanging Unidentifiable Items that you may not need.

Given that Tier V materia is much easier to obtain than ever before it's definitely time that G4 Carbonized Matter became equally as obtainable. Ideally, at this stage in the expansion, it should be available via retainer ventures (at 20-30 per hour). Arguably G5 should be also added by now. At the very least G4 should be on far more gathering nodes, even lvl50 HW 'standard' ones.