How to switch jobs after a fixed time?

[ElizabethD]

8910, and relatives, have a COM/Skip button.
I tried it the other day in unextended remote, using instructions from the manual. It worked. During the time set for the button, I switched devices, settings, all sorts of things. It came back when the time was up, to the original TV channel. Now, I don't care about that kind of use. As is, mute & close your eyes does the job.

But, there were several threads where people want to do something on another device, and 3 minutes later to revert to where they started from (i.e. I suppose after the last keystroke in the detour, I haven't designed it in my mind). Pause(s) is not a solution, as it sits and waits for a key.

Com/Skip is designed just for numbers. Can we beat it? Instead of programming channels we could program some macro on another device. I tried it directly on the remote, but it said "INVALID". It also would not take shift-number (where a macro could be).

Clearly, when Com/Skip job is being setup, there is a countdown timer(**) in the picture. Up to 3 minutes in 15 second intervals. 8910 is watching the timer interrupt (which? where?) and finishes the job by switching a channel.

While the clock is ticking, the remote is NOT watching the keyboard. It seems to me we should be able to use that timer somehow, but how? If this is a goofy idea, why?

Sorry for the rambling loud thinking. I'm unable to ask it in any more coherent way.

(**) Do both extended and unextended L/DKP protocols (executors?) really use Timer0?