I’ve done the register, and CHIRP happily will try to write an mmap (since the file isn’t .img or .ftxd, it seems to look OK.)
But I cannot convince the CHIRP to read the file. It looks as if it’s trying to decipher the filetype in order to determine the type of radio. I’ve tried enclitics like “sdc1”, “sdc2”, … for each radio but it doesn’t seem that the directory points to any driver. The error is
ERROR: <function ChirpMain.open_file at 0x11c6efc40>: Unknown file format
which looks as if it comes from chirp/directory.py L171
It's really hard to say without being able to see what your changes look like, and a real traceback. However, did you modify match_model() to agree to load the new file type?
https://github.com/kk7ds/chirp/blob/master/chirp/drivers/ft1d.py#L888-L892
--Dan