The JT strong arms work..... BUT, if you have the electric jacks where both legs come down with one switch and adjust to uneven ground automatically.... One should think it over.
That style of jack has a huge advantage in that it keeps even pressure on both legs. Even when settling into the ground. This makes it impossible to rack the frame causing the doors to stick etc.
Using JT strongarms with these jacks interferes with the equal pressure feature. So using them together on a surface which will allow settling could be a bad thing. Using them on a solid surface slab would work fine.