It used to be that you'd get an error if you tried to buy an item from user shops with a full inventory, but I'm not getting that at all today. I currently have 130/100 items in my inventory, and I'm surprised to find that I can still buy stuff.

Was this an intentional change, or is something broken?

i ran into this the other day without realizing it (finished questing to find my inventory well over 100), and i want to say it might be leftover from when the inventory had 1000 items for lumi presents? maybe the inventory wasn't completely reverted after presents went out?

it's still happening; i have an inventory of 110 and i can still buy things just fine. edit 3/18 i don't know quite when this was fixed but it is, i think! i just got yelled at for trying to buy from a user shop while having a full inventory.