hi tx and WELCOME to the forums...
folks don't realize that with these looooooong units even a little slope is significant.
the jacks and tongue function without issue fully extended...
but it takes a long time to retract them once out.
consider adding blocks UNDER the jack pads and under the tongue stand to reduce extension.
i've been in sites where even fully extended this was necessary.
also with so much slope, make sure the tires cannot roll even a tad...
i use
rotochoks purchased at the a/s dealer in weatherford tx...
Rotochok Online
once these are in place, there is NO tire/wheel MOVEMENT
cheers
2air'