I used to build my mopeds in my dining room.
An upside down bucket is good to sit on.
If I had enough money to build a nice work bench, I’d probably spend it on more mopeds.
Seriously, I can’t think of much. Mopeds are super lightweight and simple. However, rolling with your wheel chock idea, maybe have some full length angle to both support the wheels and place them perfectly in line. Not a big deal, but it would be nice to shim wheel spacers and know that everything is as good as it can be.
A 12V power source for a timing light and some convenience outlets.
Super fancy would be a vented exhaust collector.
I’m out of ideas.