[FrodeSolheim]

I don't think there should be any difference in compatibility compared with WinUAE (but I'm of course interested in proofs or strong indications of otherwise).

Note, the option unsafe_save_states does not do anything other than unlocking the GUI for allowing saving/loading state for HD-based configs.

The option relative_temp_feature is required if you use the Launcher's ability to (for example) automatically assemble a WHDLoad hard drive based on config from the online game database and indexed .lha archives. In this case, the automatically generated hard drive gets a new temp path each time you run the game, and relative_temp_feature just instructs the launcher to do this in a way that FS-UAE sees the same paths every time. Otherwise, savestates would definitively not work in these cases.

(It you use static directory hard drives like you would in WinUAE, relative_temp_feature option is not needed)