Choreographing Percussion Parts

I’m faced with a dilemma...

I imported a MusicXML file which included six percussion staves each set to a particular percussion instrument.

As we know, apart from important timpanists; percussion staves in scores are labelled by ‘Percussionist’ and not by instrument, because percussionists can jump from one instrument to another, as needed.

When I first imported my MusicXML file, I set each percussion stave to its percussion instrument using the ‘Part Properties’ window.

Now I would like to choreograph the six percussion parts, as they can be handled by just four percussionists. I need to reduce my six-stave percussion score to four staves showing instrument swaps etc.

(i) Is it best to edit the percussion staves I already have, or to insert new percussion staves, copy and merge into these from the old percussion staves and then delete the old percussion staves?

It’s frustrating that at the MuseScore Handbook here:

https://musescore.org/en/handbook/mid-staff-instrument-changes

…it says:

‘Mid-staff instrument changes are limited to the same type of staff. For example, you cannot change between a percussion staff and a pitched instrument staff or vice versa.’

…by definition, percussion instruments can be un-pitched and pitched! (ii) Why shouldn’t a player be able to switch from a shaker to a xylophone mid-score?