Louis D

I've owned several truss dobs, and not one uses grease on the side bearings. Virgin Teflon blocks riding on Ebony Star Formica (or equivalent) should need no additional lubrication. Nylon blocks can be substituted for Teflon to add a little more sticktion.

You might try mounting fans to blow across the front of the mirror. I've heard good things about this approach removing the boundary layer of air just above the mirror. Kind of counter-intuitive.

If the bearings had been teflon on pebbly Formica, no lubrication should have been needed at all. In fact, the motion can be too smooth with too little sticktion to hold heavier eyepieces. Reminds me of the Stabilite mirrors that Zambuto abandoned over a decade ago because it was too expensive to deal with print-through issues during figuring. Has Sky Watcher found a way to deal with this? Both were/are radial rib designs.