BAL type landing legs much less stable than scissor jacks?

As you have discovered, the scissor jacks are indeed more stable than the stab jacks.

I added some small jacks directly in front of the TT wheels. It also helps to tighten the stab jacks every day, as I have found they loosen from movement inside the trailer.

JT strongarms or steadyfast system should also solve the problem.

I've been kicking around the idea of the steadyfast system on mine.