Hi, I've started playing with your mod recently and Its really cool but only for vanilla playthroughs.
But after playing with it for a while, I came up with this idea: Instead of showing visibly the items on top of the screen, you could list them inside a suspended list just like black market 2 does. Only has 1 button and a small window pops up when you click it with the items and their prices. You could do something similar but listing items and quantities on that window, so it wouldn't clutter the top of the screen. Or maybe allow pinning items on screen so they would behave like they do now but player would toggle which one they wanna see all the time on the screen.

And, the list could be extended to embrace ALL items, even modded ones, doing a scan at the beginning of the game like most mods do and then indexing the items to be pulled/pushed by the mod.