It depends on your microwave. Our one at home has a metal flat rack that slides in like a typical oven rack when using convection. Our RV convection is a Sharp. It has two round racks, high and low that sit on the turntable. You can put food on both racks and while cooking. Having the turntable on, helps with even cooking. On ours, you can turn the turntable off so when we put in a cookie sheet, it doesn't try to turn.
I do most of the cooking and I originally feared the convection oven. I finally decided to give it a try. One of the things that I didn't like about it, was that it had a long warm up time, over a half hour. To me, that just didn't make it convenient.
To circumvent this long warm up time, I would just turn up the temp and put my food in right away. As an example....if I was typically cooking chickn at 350, I would instead put it in at 400. I know the chicken we usually eats takes baout 35 minutes. I set the oven for 40, so I could stop it at 35 minutes and check it, without changing my settings, in case it wasn't done.
I find that I can make chicken, ribeyes, pork chops and other meats juicier by cooking them in the convection oven. The way I do that is to use those black BBQ mats that everyone sells, I cut them to fit my racks and then place my meat on top of the BBQ mat while cooking. The juices stay on the mat and in the meat.
I created a 3x5 card that I write down the times and temps I used to cook certain meats, since we usually use the same cut of pork chops, chicken, etc. Now I can set the convection, throw in the meat, set it and I'm done.
Don & Mary
2019 Newmar Dutch Star 4018 - All Electric
2019 Ford Raptor Crew Cab