Relative mouse mode - regressions in recent firmware?

That sounds good; although from your comment above [I’ve tested it, and it seems our frontend doesn’t support older versions of mice], it sounds like that may not fix my issue? Can you elaborate on what you mean by “older versions of mice”? Maybe I’m misunderstanding.

Is the ‘two mice’ behavior coming from the underlying pikvm code? Would I be able to disable it locally with an yaml override such as

kvmd:
    hid:
        mouse_alt:
            device: ""

?

To answer your question, my setup is unusual, in that the controlled computer does not have USB at all. I am relying on USB to ADB converters. I’ve ordered a different converter, to see if perhaps the one I am using does not handle multiple mice being connected gracefully.