YAY, serendipity rocks! Found info on this during a ridiculous 24 page sifting expedition in Hacks & Development. Sounds like mouse function would be the impediment:
I'm wondering if the USB Wombat from @bigmessowires can bring mouse function back up to snuff at 20MHz? That's the target clock for my KLUGE (insane functional equivalent) I'd almost, but not quite wager its ADB input is a far cleaner signal than a 30 year old mouse can achieve? Thinking clock synchronization/bus speed borkness?