Still, I'd prefer not to have to manually change the playback mode in the settings every time I switch from an Amiga MOD to a PC format. DeliTracker and EaglePlayer supported multitrack formats but played the aforementioned modules correctly without any user input. I somehow expected the Normal/Default playback mode in XMPlay to do the same.
I can't think of any algorithm that would be able to check whether panning commands are supposed to be interpreted or not for 4-channel modules, since there is no
way to determine if a 4-channel module was made on PC or Amiga, let alone with which tracker. Deli probably simply doesn't support 8xx panning in MOD files at all. Or maybe they use the file extension to determine how to play the file, which is also a bad idea since file extensions should never be trusted and there are many MOD files made with FT2 that have the .MOD extension anyway.
The best solution in XMPlay for your problem would be to use the saved settings feature; Set up a default player profile for all MOD settings (such as interpolation, MOD playback mode, etc) and then create separate player profiles for individual paths or files which override the default MOD settings. That's what I use for my whole module collection and it beats any "automatic" playback detection algorithms by far.