Mid-staff changes between unpitched percussions and other instruments
«If possible, use a single stave for a succession of different tuned percussion. The more vertically compact the layout of the part is, the faster the player can read it... Notate instruments of indefinite pitch on either a conventional five-line stave or on one to three lines... For a multiple-instrument part, players prefer notation on one five-line stave... The treble and bass clef are used only for tuned instruments; do not use them for instruments of indefinite pitch... Instead use a clef of two lines (the ’percussion clef’) that ’cancels’ any assumed pitch» (Elaine Gould «Behind bars»).
E. g. I want to write a standard drumkit part with a solo fragment in pitched tom-toms or something like that. It's easy on the paper — just change the percussion clef to the pitch clef and write a text cue «mute in Rototom...» I'm afraid it's impossible at all in Musescore, or, anyway, I have no idea how to glue it.