Buzz.... reading that mess made my head hurt!
WTF is going on in your customer's home and what remotes are you using? None of that made any sense what-so-ever if you are doing it correctly.

My customers pick up a remote, there is an ON & OFF button at the top. They select what they want to do on the remote, and it does it. They are using the system, and the remote tells them at the top what they are currently doing.
How the hell can it be any simpler than that!
And I always gather up all the OEM remotes, take the batteries out, and put them in a large ziplock bag. That bag is placed somewhere near the equipment, out-of-sight with a couple of batteries to install when needed.


[In other news]: I constantly have to go behind other installs fixing remote programming. I don't think I have ever walked into a house down here, that had a remote programmed properly. It's like these a-holes sleep thru the basic training courses (honestly I don't think they take it at all).
This causes even more animosity for the customer towards "universal remotes".... because of idiots!

Which will bring us to the topic again: If the customer just has a few devices (TV, soundbar, streambox), there is no need for a universal remote anyway.

Apps... Apps are the last f^n thing to be used to control anything; except audio only systems, whole house systems, and one off IoT devices. Anyone trying to use an app to watch TV, well... they deserve what they get. Including anyone on here that wants to argue that one - enjoy your masochist.