Yeah, when I first looked for the Mule 1 or 2 years ago, I also tried out all the hover scripts I could find. Definitely we all have our preferences, but it's also cool that SE now supports that kind of design without being all janky like voxel sensors. I personally like Naosyth's Flight Assist the most, even though the script is a bit outdated with how it handles the required assigned group of blocks (and I haven't learned yet how to fix that).

It's got a script that handles all that now, but I like your idea of vanilla without scripts.

Also, now that event controllers are in, I used a concept that Rogers has on their ZT-whatever Star Wars speeder bike. They used sensors, but now we can use event controllers, which are MUCH more reliable and fast at detecting voxels via altitude detection.

A simple setup for low-altitude hover effect: Group all Up thrusters. Add two timer blocks, one to spam increase thruster group override by self-triggering loop, one to spam decrease override. Add two event controllers, called here Min and Max. Set EC Max to detect altitude 30 or greater. Set up EC Max actions 1 and 2 as Turn Off group, Turn On group. Set EC Min to detect altitude 10 or less. Set up EC Min actions as trigger Timer Increase and Timer Decrease.

This should shut off up thrust above 30 meters, and max out override thrust below 10.

There's a plug-in mod for additional thruster actions: Max override and Min override. This can elegantly eliminate the two timer blocks with single actions on the EC Min.

Your ceiling piston connection is sweet. I cheaped out with only a single hinge connection, and it necessitated a bunch of high catwalks and some gymnastics to enter the Mule's seats from the ceiling.

For the wheels, when I looked at screenshots of the Mule, I opted to only mount two sets of 3 1x1 wheels only, no suspensions. I used those little tiny corner blocks to mount them on the lower outer front corners of the cargo arms. Minimally useful as bumpers. Had to drop the bottom pair of mag plates to fit this.