Published Mail Keyboard Shortcut Shift-Command-O Doesn't Work

I'm looking for a way to easily move messages to folders in Mail.app (which every other mail app [and its mother] offers out of the box.) Apple has a support document with Mail Shortcuts ( here ) which includes

Quickly Open a Mailbox

Shift-Command-O

In the search field that appears, start typing the name of the mailbox, then choose the mailbox from the list of results.

This doesn't seem to work. I've tried on multiple Macs, including launching in Safe Mode, guest accounts with no modifications or extensions added etc.

I opened an Apple support ticket about this a few months ago and they haven't responded.

Wondering if anyone has been able to use this shortcut command? And if so, how?

The impetus for wanting this is the next version of MacOS is going to disable certain kinds of plugins from functioning in Mail.app and I've been using the MsgFiler.app for many years for this which will no longer work when Sonoma is released. (More on that here.)This is likely the single most used piece of software on my Mac which has allowed me to quickly move messages to mail folders, create new folders on the fly, and it works better than an of the other implementations I've seen in other mail apps (and I've tried them all specifically looking at their moving messages functionality.)

I really don't want to move to another mail application. I have about 20+ years of mail in folders in my mail database so it's a real bummer Apple is removing the plugin ability to work with the next version of the OS.

This would be moderately better if their actual published mail shortcut Shift-Command-O actually worked.

Any help or ideas would be appreciated.