I built a vertical 3pt hitch splitter in 1978 primarily do deal with all the big elms that were dying.
The weak point on a splitter with a travelling wedge is the junction of vertical back and the horizontal table.
It is almost impossible to make the joint strong enough while keeping the table close to the ground.
I needed to roll 40'' diameter logs onto it so it had to be low and one has to chip away at the log as they are too big to split in two on the first split.