the separate outs are stored in current panel, if you don't want them to change, don't load current panel on page 2 of the load page and press panel memory 1 to set up start conditions or use sequencer panel write if a song.
For midi files, load, set up outputs, then save as Technics, page 2 save sequencer and current panel only. The bass track 'may' change between different sourced midis anyway so has to be set up individually.