I had a go some years back after getting my first 5232X, but I didn't pursue the idea too far as I couldn't replace the drive if it was bricked.
The Plextor EXE can be opened with 7Zip and reveals a firmware BIN, the flasher (PXFirm_B.exe) and an INI file. The INI file looks very promising and I experimented with changing the drive name, but was unsuccessful.
Alas the Benq all-in-one flashers aren't so obliging, but it may be possible to unpack the EXE using other tools.
As far as I know there are no 3rd party firmware tools for Ali-based drives.