The cpmboot disk image performs some weird remapping of the ASCII codes sent by the keyboard. Y and Z are interchanged (this is probably a German version of the OS), @, ^, * and ( become ", &, ( and ) (as on a bit-shift keyboard), & becomes /, < and > become ;, / and ? become _ and -, ] and } become + and *, # isn't recognized, etc. Clearly it expects some different keyboard model.
I performed some further experiments with the MAME source. I hooked up my new keytronic_l2207 emulation, and it surprisingly proved to be almost entirely compatible with normal Kaypro versions of CP/M; even the non-ASCII codes for the numeric keypad are OK. (The Set-Up and PF keys do nothing useful, but that's not terribly surprising.) Even more intriguingly, the primary dump exactly matches that of an INS8048 somebody dumped from a Kaypro II.