I tried to generate proxy and Spartacus failed with null reference exception. Reason: my DLL has no version info. After including dummy resource as suggested here, everything worked fine. I believe this can be fixed in GenerateResourceFile to expect null versionInfo or its fields:
https://github.com/sadreck/Spartacus/blob/main/Spartacus/Modes/PROXY/SolutionGenerator.cs#L130