Want to add there are "U-Rest" stops that are for people who may want to take their mask off and relax. There are a couple around each park. Usually, they have signs directing you and letting you know where they are once you're near them.
Universal at Central Park and Fear Factor.
IoA in front of the lagoon when you first enter the park and where Sinbad's stunt show was.
City Walk's is near the water and by the Universal entrance area.
I did mobile order and for the most part went according to plan. I specifically did it for Louie's. The tables seemed pretty decently spread apart. Other than that I do not much experience with QS since covid (been mainly going to table service restaurants), but might get more as time goes on. Only issue I had was I had to put my table number manually in the app table rather than scan the table where it directed me to. However, it seemed easier and less confusing to just go forward and just enter the number manually (it's a short number anyway). I recommend trying to ask for salt, pepper, sauces, ect, when the person brings your food, even if you're unsure you need it, just do it just in case. As I realized I needed a few things afterward (when I realized my food lacked flavor) and it was awkward trying to ask them for other stuff and I even confused two of the TMs (long story).
If anyone has issues with the app I'd suggest turning off and back on your phone (this is standard for any issue) as well as making sure your location on your phone is on. From there, if it's still not working you obviously would just have to show up and do things the old fashioned way.
I also suggest scoping out places before you may order if safety is a concern for you. While I didn't do that and luckily it felt like a safe environment. All restaurants are different so might want to take a peek and double check the seating arrangements if it's really a concern for you.