Levelling blocks for camper on driveway with 2 degree grade

It's funny you all say that you n need to support the base with something under it when the 2010 Lance instruction manual specifically says not to do that?

Ok since sliding is a concern should I use typical plastic blocks then? The truck camper is also going to be unloaded during winter and there may be some frozen moisture though I will clean it best I can.

If anyone can recommend a product I would appreciate it! Thanks!