I have rotary processed plenty of APX100 in a Jobo rotary system, mainly 135 but also a reasonable amount of 120.
D76 1+1 works beautifully.
I do not use a pre-wet, just drop the developer straight in and away I go. With this method you can pretty much use the Ilford/Kodak inversion times as a starting point. You will be able to fine tune your negatives after a very short time.
As you are diluting the developer and using smaller amounts be careful of over diluting the chemicals. I have had great success with a rough working method of 4 rolls per 500 ml of 1+1 D76 solution, or 2 rolls in 250ml.
Mick.