UHMW could be used to repair the hard plastic covering found under most Schwintek slides.. The tolerances for the In Wall Schwintek slide out could easily be measured..
The one to pay attention to is the V roller guides.. You have four of these.. one located on the top and bottom track guide of each side of the H rack.
The V rollers should turn with finger pressure.. If they are too tight to turn with finger pressure then adjust the slide bottom roller heights slightly to lower the slide bottom to allow for proper V roller movement
If the V rollers "Free wheel" then the slide is adjusted to low on the bottom opening slide rollers
UHMW cab be bought in thickness of 0.125 (1/8) sheet thickness. It is what I would use and then adjust the In Wall slide bottom rollers IF my four V rollers were too tight on the guide tracks
I I had an area on the hard bottom plastic that WAS NOT in the path of the bottom rollers then I believe I would secure with small pan head screws and apply some black sealant over the crack joint as well as the screws themselves..
A couple of images to illustrate the V rollers and vertical measurements.. Height wise measuring from lower right and lower left should be within 1/8 inch from side to side on the vertical height
I also do not think UHMW would affect the operation of the top wiper seals .. especially if one pays attention to the guide track V rollers
https://lci-support-doc.s3.amazonaws...cd-0002661.pdf