I don’t… not even for challenge events. I’m just in it to complete it. For challenge events it’s too much time investment for rankings, for me. For the NT, just getting to end means a lot of emblems and a possibility of a 4* AM… and another shot for Dawa in the ninja summons.
For class trials, I don’t usually need to use items, although the last one (druid/cleric), I had to, surprisingly. Maybe it’s due to the lack of heavy hitters on my part.
I just completed upgrading my HL a few days ago. Now the question is what is worth researching. Probably just going to stockpile harpoons in the meantime.