I have the UPC TV box and use it with a third-party (IR) remote. Almost all the functions work. The one with three dots can’t be mapped, and the “back to TV” button was removed as an IR command in a recent firmware upgrade for some reason.
The rest work, and I programmed my remote to substitute the two that don’t.
However, the official remote is bluetooth, so you do need to program something else (Logitech Harmony in my case, although they’ve been discontinued).