Well first off getting this as expert exclusive would seem unfair to the summoner class as it is already one of the hardest classes to even use, especially in expert mode. The treasure bag idea Needs you to defeat moon lord in expert and seems unfair to summoners who don't want to take 300 damage a laser shot while doing minimal DPS. The using developer vanity would cause you to have to open around 20000 Treasure bags to make it... and could be gotten early hardmode with enough grinding. (Pretty unlikely though)
I want to stick with it just being the way it is, I think it's fine with the drop currently .
Also edit to the thread, about to change some stuff up! Will change up the beta situation. I'm still looking for a good Crowno and Red attacks, I can't seem to think of any currently should be able to add them if I think of anything soon!
It's currently kind of late and I'm about to eat dinner, so changes may occur in the next few days over the weekend!