I have found that if my first leveling action is to put the Bigfoot into "Manual" and then raise only the rear as high as it will go it "dumps" the air from the rear suspension. Then I retract the jacks and return the Bigfoot to Automatic and let it level the coach. This seems to level the coach without raising it up excessively, whereas if I just go Automatic from the start it seems to want to raise both ends higher than I think necessary. Perhaps this is because the air suspension is still "full" right after parking.
I don't know that this affects the "scooting" all that much; to combat that movement I always chock the front wheels with two pair of large rubber chocks I got from Amazon. Here is a link to them: Robot Check
I connected each pair together with a rope with a snap clip in case I need to split the pair. The only problem is that these chocks have a very strong "rubber" smell even a year later! They remind me of my youth when my city was the "Rubber Capital of the World" and millions of tires were made here annually. That same smell was in the air constantly!