Desynthais broken for blacksmith at higher levels

[Marcux]

There are certain desynthases crafts like goldsmithing that have craftable i90 accessories (gold specticals, etc) to put materia into and desynthable. The problem come with blacksmithing.
#1 there are no craftable blacksmith items above i70
#2 highest weapon to be desynthable is i80 (titan) it's primal weapon, and cannot use materia to increase the percentage of desynth.
#3 cannot desynth allagan weapons, levi, etc. How does a blacksmith hit 100 desynth? not possible, hoping for a mod response. this seems broken.

Goldsmith has Gold specticals and can use materia to higher the percentage
Armorer can make i90 armors with Materia
Leather worker can do the same,
Weaver same etc

basically every job except blacksmithing