Today, I learned new things about materia:

[Sated]

-You can desynth stuff in instanced/duty-finder content

Learning I could desynth while running was a revelation.

Yes, but only on certain gear. Crafted gear can be pentamelded (5 melds), but gear you get from dungeons/raids/tomestones can only accept materia in slots.

Ah thanks good to know. I planned to look more into it when the time came. I mostly just want to deck out my gathering set.