What could there possibly be to say about using Shift + F10 in XPP?

Not much, unless it suddenly stops doing what it does, which is to insert the special XPP tag brackets. So, if you like a bit of a puzzle, don't read too far ahead.

What could make Shift + F10 not work, assuming nothing else has changed in your XPP environment?

In my case, I had another software application running in the background. It turned out that that application was also using Shift + F10 for its own reasons. In my case, the app was Snagit, a perfectly fine piece of software, and I'm not intending to cast any blame. Snagit uses Shift + F10 to stop the recording of a screen capture video. I did have options: I could just run Snagit as-needed (instead of always being "on") or I could change the hotkeys Snagit uses. I elected to not have it always running in the background.

This could possibly happen with other third-party software that is running on the same system as XPP. It's probably a fringe case and maybe not something that will ever affect you, but, hey, you never know. Now, how long did it take to figure out what the problem was? For me, far too long! So that's why I'm sharing.