Does anyone make an RSH for an AppleTV4 and Roku on the same faceplate?

RSH is a Middle Atlantic model number, so, yeah, them. But you have to wonder if there have been enough calls for that particular combination that they actually have any of them in stock. Give them a call and ask. We had to do this recently with the AppleTV4 and the Extron OTA TV Tuner. They knew dimensions for both pieces and so could fabricate the double mount.

If they don't have the dimensions for the product you want to mount, they have a very clear form for defining the dimensions. We did this a couple years ago and the panel was spot on.

Yep. We've done this several times for devices that weren't in their database. If you don't want to measure you can send them the device too. And yes they will do a dual horizontal RSH mount of different devices...if they fit, which in your case they will.