I had a shop install the RJM pedal since they were doing a bunch of other things as well. There seems to be a lot of lateral movement on the pedal arm/elbow (everything except the base), and it's become a lot more apparent as I drive it. Like it'll slide up to 1/4" side to side if I leave my foot on it. Yes, I know I should've driven it around for 10-15 minutes before heading out, but I'm an idiot and wanted to get back to work... I've asked if they could take another look, but I wanted to make sure that this isn't normal. I took a quick look under and couldn't find anything that was loose or obvious. I'll go back under tonight and see if I can mess with some of the nuts.

 

You mentioned that the base seems to be ok but I would double check the nuts holding it to the firewall.
I know it was a little bit of a challenge to get to the bottom nuts and needed a couple of different extensions to get them nice and tight.

 

Edit: I talked to Ryan from RJM and he said to adjust the 7/16 nuts at the top of the arm. This firmed everything up.