I'm not sure what debris you may get under the topper. However if it is something like a tree branch of pine needles I would get them out. You don't need that type of stuff getting against your slide seals when you close the slides. The purpose of the slide toppers is to keep debris off the slide themselves. However if you get something under it you really should get it out before closeing up. I have a folding/collapsing ladder I carry with me and I use that to get up to where I need to be.
Tony & Ruth........... FMCA#F416727
Newmar Dutch Star 4320, Spartan MM Chassis, Cat C9, Jeep Grand Cherokee,with Hemi, hooked up with a Blue Ox Aventa LX, and Brake Buddy.