Hi Scott, here’s an option depending on what types of activities you use on that TV. Create duplicate TV activities. One with the fireplace in it and one without. If you just want to watch tv, you can press the one without. If you later decide you want it on, you can press the one with it and since everything else is the same no change in buttons or anything. If you have a lot of activity types (cable, Apple TV, bluray, etc) it could be tough.
The home companion remote has 3 dedicated activity buttons, but each can store a short press and long press; so you could map the fireplace ones to long and without to short. If you have more than 3 TV activities, you’d be in a pickle or need the Elite.
Then you could use JD’s virtual switch suggestion to put the fireplace only activity to one of the 4 home control buttons for when you just want the fireplace and not tv.
Lastly because you’d be switching activities but with the same devices, you’ll want to play with the advanced settings for not changing inputs, so you don’t get the input selection flicker when making a change.