If you are going to be set up on a concrete pad permanently then maybe but otherwise no on the stands. The slide is sealed by the way it fits in the sidewall so to tight on the stands you will have a leak and too loose then they are doing nothing. I also agree that the PDI is only as good as you make it. If you don't ask them what something is or how it works they may assume that you already know. With the exploding sales of campers they may have 10 or more to deliver that day so they want you out as fast as possible.
With all that said Welcome
If you have any more questions please feel free to ask
There are some good folks here ready to help.