I'm using al v2 stuff.
When I put the TX about 8 ft off the ground with most of the receivers 6 inches to 2 ft above the ground, all of my "lower channel glitches" went away.
I had to pull the RX from the DMX SSR4s - I saw a lot of rebooting with these and never could achieve stable operation. Fortunately I had a second RX/TX that I could set up as a receiver for the units in that part of the yard.
I've got one RX where I replaced the reistors going to the LEDs that I am testing - used 4.7K for the power LED and 1K for the data (my highly scientific methor for selection included looking through the parts box from another project to see what I had on hand and trying them to see the biggest resistor I could use and still be able to see the LED light up). The LEDs work fine, but the RX board is still pulling between 77 and 79 ma, which seems a little high, but I haven't had tme to play with it and I was using the 3 dollar multimeter (not the good one)...
RM