Key signatures behave weirdly after switching from an unpitched instrument to a pitched one

OS: Windows 10 (10.0), Arch.: x86_64, MuseScore version (64-bit): 3.6.2.548021803, revision: 3224f34

I think this could be seen as one or more issues, but I'm not 100% sure, so I'll post here first. Below is some introduction for context, but the actual bug is described at point 3.

Percussion players (in concert bands, for instance) often need to switch between pitched and unpitched instruments. Support for switching between percussion clef and treble clef was, I believe, recently added, which is fantastic news for orchestra composers! However, it still causes a few problems.

The attached score shows two different approaches a MuseScore user could take when writing for a percussionist that needs to switch between Vibraphone and Concert Bass Drum, in two different orders:
(a) Playing vibraphone first, then bass drum; using the Concert Bass Drum instrument
(b) Playing vibraphone first, then bass drum; using the generic Percussion instrument
(c) Playing bass drum first, then vibraphone; using the Concert Bass Drum instrument
(d) Playing bass drum first, then vibraphone; using the generic Percussion instrument

Each approach has its issues, which makes such a piece impossible to write without the hassle of creating multiple staves for the same person. Some of these make sense, but it would be great if there was at least one way that actually, completely works.
1. Switching between 1- and 5-line notation is impossible, meaning (a) shows the bass drum on the wrong line and (c) makes the vibraphone impossible to read.
2. (c) and (d) don't add a treble clef automatically when switching to Vibraphone. Note that the treble clef still does not appear on the next system. Can be fixed by simpy manually adding the clef.
3. The main problem: key signatures behave weirdly after switching from an unpitched instrument to a pitched one. It seems like unpitched instruments are always set to C or - if there used to be a pitched instrument on the same staff - the previous key.
- Try adding a key change to bar 3. The effects show on (c) and (d), but the new key is never shown, not even on the next system. (a) and (b) ignore the new key in bar 5.
- Try adding a key change to bar 4. Three sharps appear on the end of the first system, implying that we're modulating to the key we're already in. Again, (a) and (b) ignore the new key in bar 5.
- Adding a key change to bar 5 works as intended.

Because of problem 3, even option (b) doesn't completely work. Any workarounds are welcome (except the ones where I just add extra instruments and click "Hide empty staves").