I have used BAL X chocks since 2008. Old fiver was 36' and a bit north of 12,000 pounds. I was able to park it on some fairly steep sites with ZERO issues.
If you find yourself on a steep slant, just lock in the chocks BEFORE you unhook.
2012 Copper Canyon 273FWRET being towed by a 1994 Ford F350 CC,LB,Dually diesel.
Airlift 5000 bags, Prodigy brake control, 5 gauges on the pillar.Used to tow a '97 Jayco 323RKS.
Now an RVIA registered tech. Retired from Law enforcement in 2008 after 25+ yrs.