We just got our Cougar 29BHS on Friday and we have already learned that it will level to what the system "believes" is correct. An example is if the DW is messing around with getting things out of the storage boxes, the system will detect the weight change and adjust itself. So, if the slide is extended, then the system will be able to tell and will try to adjust accordingly.
After having our system do the auto-level on Friday evening, I ran it again after we had everything packed and ready to go on Sunday. Although it was pretty close to level to start with, it still had a couple of minor adjustments to make.