There are more than a few third-party LCD displays available for the RPi 3 B+. Most fall into two categories--those that use the RGB LCD HAT as an interface and those that use an LCD Driver board and 5-button UI board. In the 7" size, these boards are generally rated at 1024x600 resolution. I have purchased two (a non-IPS display that I immediately put into the parts bin, and an IPS screen that I am currently using). It is rated at 1024x600, but I've tried everything up to 1920x1080 and they all seem to work. This is just a plain LCD without touch input.
So...two questions: 1) am I seeing true 1920x1080 or is it falsely reporting this resolution, and 2) if this is a true 1920x1080, am I running any danger to the screen or components by running this resolution continuously?