Handbell Pitch

https://en.wikipedia.org/wiki/Handbell seems support your claim:
Handbells are a transposing instrument, meaning music is written one octave lower than the sound the bells make, so a middle C bell is playing the note C5
Workaround is to set that transpositiong yourself via staff/instrument properties.
Not sure though how that's going to work without using the ottava bassa clefs

"Not sure though how that's going to work without using the ottava bassa clefs"

Would one not just add the

transposeDiatonic
transposeChromatic

tagsto the entry in the instruments.xml file for a Handbells stanza?

True of course. so would the attached pass muster?

Jup, that sounds and looks correct. Will you log the PR to fix instruments.xml?

Aside - I really struggled to escape the less/greater than brackets when trying to quote that text in this edit box - gave up and made a screenshot. Do you know how to escape a block of text, and not the individual chars, e.g. turn "empersend-char"lt into
<

The instruments.xml for master/4.0 will get generated from a spreadsheet that Peter Jonas has tucked away somewhere. Notified him on Discord.
Meanwhile and for 3.x I'll add it to https://github.com/musescore/MuseScore/pull/9000

You can use <xml>...</xml> to show xml code

Good to know, thanks, and thanks.

Do you set this Issue to PR created once you have added it to your PR 9K, or (since 3.6.3/3.7 won't be an official release), leave it open until master/4.0 includes the updated file?

I'll leave it to Peter.

Ready-made instructions for Peter (copy and paste ready). Add to stanza

 
<Instrument id="hand-bells">
the following 2 lines
 
                  <transposeDiatonic>7</transposeDiatonic>
                  <transposeChromatic>12</transposeChromatic>

PR: https://github.com/musescore/MuseScore/pull/10663

As requested, 8va octave clefs will not appear in normal transposed pitch mode. However, 8va clefs will appear in concert pitch mode. This ensures that the notes remain on the same staff lines in both modes.

Fixed in branch master, commit 03bd6187a5

_instruments.xml: Fix saxophone pitch range and hand bell transposition

Run share/instruments/update_instruments_xml.py to fetch the latest
online spreadsheet. Changes introduced here:

Resolve https://musescore.org/en/node/329569 - Saxophone pitch range.

Fix #328336 - Hand Bells should sound an octave higher than written._

The templates have not been adjusted yet though, but, citing Shoogle:
The plan is to remove all instrument data from template scores so that only the instrument IDs remain: the instrument data would be repopulated when the template is opened based on current data in instruments.xml. But if we don't get around to doing that then we will indeed need to update the existing templates with the new data manually.

Automatically closed -- issue fixed for 2 weeks with no activity.