I've been running a mini ex for a few years now and mostly working solo as well as staying under CDL territory. Sounds like I'll fit right in on this thread...
Excavator is a kubota kx-91 which weighs about 7300 lbs with grapple. I run it on a small equipment 12k equipment trailer (derated to 9999) that weighs about 2300lbs, this gives me a few hundred pounds of wiggle room for extra attachments.
I can also squeeze the mini into my 6x12 14K (again derated to 10k) dump trailer but I'm probably right on the ragged edge of staying at 10k on trailer axles. It's not an ideal setup but works in a pinch. The bonus is using the trailer with the mini ex to forward logs or debris.
Essentially I am never on a lawn here in CO, usually working in the woods so there's hardly any drawback to the mini ex. When I lived in the NC mountains I had a dingo that was much easier on lawns or would mat for the excavator if needed.
I'd love to see even smaller wheeled excavators than what
@oceans mentioned above.