If the Midi file has no part markers then the file opened in RB will not have them either. Midi files originating from BIAB will have Blue and Green part markers which are retained in RB. I have a run a test transferring a BIAB file to RB via the clipboard and opening it in RB by File > "Open from Clipboard" and the part markers are retained. Note that the BIAB file needs to be expanded by BIAB > Edit Unfold before copying to Clipboard. In addition I always set the Chord Options in the RB Chord Window to "Never" automatically interpret chords when absent from an opened file.

Lyn