Yes, I think working from underneath isn't very attractive, but having a table that locks the wheels in position so you can bully the mower a bit without it falling on the floor, would be quite a help. If it had a built-in parts shelf, was at just the right working height, and you could walk all the way around it and have spanner room everywhere, the whole deal would be much better than the average work bench.
You could probably invent a bracket to let you lock the mower in position, tilted a bit past the vertical, as well.
