Or maybe I would have luck, if only I hadn't typoed something?
I am not really sure what my trial code actually looked like. But it seems to work now, so I probably messed something unrelated up.
Attached is an update_*.bin for all devices.
It should work on any device the hotfix works on. Except with less guaranteed updates.
...
NiLuJe. The comments in the KindleTool source claim that --ota targets fw 5.5.0-5.8.1.0.1
But it runs fine on my 5.3.7.3 KT as well -- do old devices not check the target revisions
at all, or does the source lie?
WARNING: No guarantees are made that KindleMenu still works on newer firmware to begin with.
In fact, the claim was made that it doesn't, entirely:
https://www.mobileread.com/forums/sho...42#post3284942
Also, I don't believe it is gandalf-compliant, so it may not run menu items with sufficient permissions.
So that may need to be fixed pronto. Especially if you want the actual shortcut to actually be operable without starting it
each time via KUAL.

And I am not sure how -- I don't own the affected devices, and anyway I know less than NiLuJe.