I was able to change the system DPI by using app settings and changing DPI for System and System UI. But I am running into the same problem with the keyboard. Even when it is set to 320, the floating keyboard and any pop up windows from the regular keyboard are fubar. I don't want to use the floating keyboard, but I can't find a way to disable it and it seems to come back periodically. Either need to fix the resolution issue or figure out how to disable some of the keyboard modes.