Me and my group have started playing yesterday and have about 6 hours in together.
Its a real slow down having to wait for people to be done with merchants especially with how easy it is to get away from your teammates and do your own thing.
Instanced shops would be great so everyone can use a merchant or crafting table all at the same time, and the instanced bit of that would make it so someone doesnt buy the same item at the same time from the vendor,
It’s slows the post adventure down a lot since we all need to go to the same shops pretty much so a change involving that would be great, or even if it only let you sell stuff while someones buying from them; like you can only have one player in each tab of the shop