I also have the Anderson jack blocks. They are more stable than wood blocks and easy to carry around.
However the Jack pad on our trailers is to small to contact the magnets, so you must position by hand.
I have the suspension lift on my trailer and do not like to extend and retract the jacks long distances, so I use a couple of 2" block on top of the Anderson.
What type of blocks are on top of the Andersons? Did you make them?
Yes I made a set for front and back. Just 2" construction lumber. I cut the corners at a 45 degree angle to fit the Andersons. Then I beveled the edges with a router. Painted them with left over house paint. Not really necessary but I had the time and materials so I made the set.