Hasu, I'll happily assume you still check this thread.
I noticed a possible omission in the USB-USB and IBMPC-USB online keymap editors.
Looking at the IBMPC-USB Converter editors for
84-key AT and
122-key Terminal, all the numpad keys are fully split, including
numpad 0. However, in the
Full-key pages, numpad 0 is not split, despite Model M full-size keyboards supporting this as well; this occurs in the USB-USB Converter page as well.
I use a Soarer's converter on my Model M (PC) keyboard with a 20-key numpad; it handles the split numpad 0 without issue (the scan codes it recognizes are EXTRA_INSERT [0xB6] and PAD_0 [0x62]). I don't have a terminal Model M at hand, but I assume the scan codes won't be too different, if at all, from these.
I think that supporting a split numpad0 in the USB-USB and IBMPC-USB online keymap editors shouldn't be too much of a hassle.