I'm not sure if what I'm attempting is even possible, but I will attempt to explain what I'm trying.
The mesh body I have supports BoM (bakes on mesh). I enjoy wearing older, system-layer 't-shirts', which render very nicely fit on my mesh avatar.
Recently, I have been experimenting (again) with creating my own system-layer items. To help with fit and placement, I was hoping to use the 'local texture' option while editing appearance. This is mostly so I don't upload items, unnecessarily.
Unfortunately, when selecting a 'local texture', saving my new item and exiting the edit, whatever region has the local texture merely renders as if there is no texture. I assume this is because the bakes for BoM are done server-side and there is no local equivalent. I tried using Local Baking/Appearance from the Advanced->Character menu, but it seems to have no effect on my mesh avatar.
I'm mostly just curious if this 'just how it works'.
My info: