Well since you’re going to call me out…
I had mine mounted differently so I could use washers to space the whole mounting assembly downwards into the ground as needed. It was slightly lower than the other wheels, but only by enough to give compression into the tiles. Because it was used for adjusting as opposed to movement, I drove it 1:1 off of a 100rpm motor. I never had any problems, and my bot weighed well more than 25lbs. (It was a conscious choice.)
I do not have any good pictures of the system, unfortunately. The SCA cad reveal that was put out at the end of the TT season doesn’t exactly do the intricacies of the bot justice, though it can give the basic idea.
On another front, my FRC team had snH drive in 2018. We had to build essentially a custom chassis for it with channels cut to move the H drive up and down as needed. At competition, however, it got pushed upwards back into the robot slowly. We consistently had to use our H-Drive Fine Adjustment Tool (a big ol’ hammer) to knock it into place after matches. But on that scale it’s easier for small movements of parts to mess up large functions.
If I were to do it again on that scale, I would use the concept presented below.
It is not my work, and I unfortunately do not have the proper credits to give. I remember that it was designed for FTC (same 18” scale as Vex), but I was thinking about it in terms of scaling up to FRC. I have done no practical testing with it.
The idea behind it is to ensure pressurized contact with the ground. You could likely get the same effect by using a joint and heavily banding the wheel into the ground such as you would with tracking wheels, for example. (Though you’d use much more banding.)
Unless you wanted to utilize a form of linear sliders in your current frame or start cutting channels for precision adjustments, there is no good way to implement a suspended H drive in your current build. I recommend you look into a redesign of your H drive setup if you want to suspend your wheel.
However, do be cognizant that, if this is for competition, the foam field tiles will be (for the most part) level, and you likely would not need such extensive suspension measures.