First off...........WELCOME AND CONGRATULATIONS ON YOU 35UN ZAPEEDO.
We are glad you found the forum and look forward to you joining in the conversations and hope you share your experiences and travels.
Secondly, our bedroom slide (31UL) has not shown any wear on the wood on wood after 2 years of use.
It certainly wouldn't hurt to put something on to help but you want to make sure it doesn't bind up and cause a problem.
Happy, Happy trails
Darrell