hi! i do have a mega drive now, but no everdrive. i could make a standalone cart with eeproms, but my supplies for that lie in my home country, to which i will not return for another year. thanks for checking in!
i’ve still not managed to grab an everdrive, so i can’t test on real hardware, but i have just pushed a version which works on the emulator that was giving you trouble. i hope that it works on your real system as well!