Hl Webbo
Confucius he say ‘ all question easy when you know answer!
This is what Mayhem is for to find people who know how something is done or how it works so you do not have to reinvent the wheel
When I bought the RME I picked up on what Engel said about needing a switcher that switched the negative. It took an awful lot of trawling of the internet before I stumbled on the Mtroniks one.
What I did not notice until the other day was the reference to item 8431. It would be helpful if they had shown the picture and price on the same page as the RME and RMR appear along with possibly a deal for the pair. Certainly they could then make it clear that most switchers on the market are not suitable.
Still in the end I think you have ended up with a switcher that is simpler to use than the Engel unit as like you have set up they operate on single switch operation so follow the transmitter switch position instead of cycling the switch for each operation. Also if you ever need a switcher again the knowledge gained should help you select the right type more easily