I occasionally roll dice as theatre myself. In my last session, I had a troupe of traveling performers that I rolled for on each act to see if they did well or not, with each roll hidden from the players, and I would then describe the outcome to them. Most of the rolls were real, but some performers I had already decided would fail from the beginning, because they were plants for the enemy faction and had a plan going on in the background that depended on their failure at the act. But of course I still had to roll to not set off any alarms. Going to be fun when my players later piece together "oh, that hypnotist didn't actually fail, they just used mass suggestion to make everybody believe they did so they don't come under scrutiny." If a player catches on - one actually did pretty quick - then great, let them have the victory, but in general it's one of the ways I like to create expectations so I can subvert them or use them to sneak things by. The enemy faction is very guerilla-oriented, so it fits their MO pretty well.
On a more general scale, when it comes to hidden rolls, if I really need something to succeed, I'll make the roll not a matter of whether they succeed, but who succeeds. Keeps the story moving if I realize too late that that roll shouldn't have happened because a failure brings the game to a halt.
I have a Mobile Pixels one, it's certainly been a big help. Power and picture from the same USB-C cable. It was kind of hard to install (have to adhesive on some magnets correctly, glue wasn't too great, I recently replaced them with some other adhesives I bought online, worked good so far).
For the most part it doesn't give me any issues, does what I want of it, but if I have one complaint it's that when I'm playing a game that uses my laptop's graphics card, I will usually have to unplug and replug the screen back in because it begins fizzling out like it's losing power or signal. Functions fine after though. It's slightly annoying but not that big a deal.
Overall I don't regret my purchase, I just wish it was a bit more polished with an easier and more reliable mounting process and not fizzling out when I play intense games.