MagicKit looks to set the screen height to 224 (going from what HuC has...), but what's worse, several emulators have their resolution fixed to this and won't display more than 224 lines... common culprits are 
MagicEngine and 
YAME, which is what started my whole resolution measuring in the first place, and which is what also led to 
this (scroll down to the very bottom).
Thank goodness some emulators like 
Mednafen let you adjust whether to clip off any or none of the PCE's full 242 lines of resolution...