Ha. I also put 32gb of RAM in mine this Summer. Figured it might be the last time I can open up a Mac to do some modifications before they become completely self contained and soldered together, so I might as well do so. I got the Apple Studio Display after doing this. So maybe with the original 8gb I would have seen issues more often.
I'm using the Apple Studio Display (it was a gift). Before that I was using a cheap HP. The 2018 mini with the RAM runs the Studio Display fine. But I do think it is pretty much right on the edge of the mini's ability to push all those pixels. I don't do any gaming on the mini. I mainly do office work. So I don't know if it would some how crap out if the GPU was being stressed.
I'm using the Apple Studio Display (it was a gift). Before that I was using a cheap HP. The 2018 mini with the RAM runs the Studio Display fine. But I do think it is pretty much right on the edge of the mini's ability to push all those pixels. I don't do any gaming on the mini. I mainly do office work. So I don't know if it would some how crap out if the GPU was being stressed.