The only issue I have had is when I blew the DC breaker when I tried to do both at the same time. Reset and no issues. They blow the breaker if you try to keep cranking them after they hit their limit. They did that during my PDI...CW what are you going to do. At least I found out which breaker it was then.
I am careful to not push them too far when raising them and putting weight on them. They were not built to lift the trailer, just hold it.