I have been using portable PDB files output by my custom compiler on desktop mono for a long while now. While I can deploy apps made by teh same compiler which run ok on the device, I cannot debug them when using portable pdb even if I hack the build system to actually include the pdb file in the apk. I end up with VSCode connected the debugger agent on teh device but no breakpionts get triggered like what used to happen with mdb files in the past. Noticing that mono in general is moving to CSC from MCS which does not make mdb files, I suggest enabled the portable pdb support in t
he embedded mono runtime also when running on mobile. I also suggest to make these build system hacks unneeded by copying the pdb files to the apk as an out of teh box behaviour.
I also noticed that the cecil tools used to convert pdb to mdb, now support PPDB as well.