No matter what I do, it keeps selecting on of those if I resize my artboard to 1920x1080, when I want it to stay to "custom" ... I'm pretty sure I'm going to be told I have no choice, but I guess it's worth asking.
Thanks for reaching out! Presets are part of the application installation, and we do not recommend removing them. Even if you remove them, they will be restored with the next update.