Had my Compaq MV920 plugged into the wall during a thunderstorm that ended up being close enough I saw and heard arcing within it so I just right now went to plug it into a Dell Inspiron 9400 I picked up a while back for $15 to make sure, since it had been kinda wobbly with a StarTech DisplayPort to VGA adapter when maxed out at 1600x1200, but the native VGA out at 1600x1200 seems perfectly fine so it's probably the adapter itself, or maybe some weird combination of any of the adapter, refresh rate, X11 possibly not liking adapters (may switch to KDE Plasma to test Wayland), and maybe something going on with the RX 570 itself. Either way the laptop went through 3DMark99 no problem at 800x600 (would have done 1600x1200 but it didn't give me the option), with a 17327 score (49661 CPU) with its X1400 and T7200. I don't know if it's the benchmark or the card itself but there was some pretty noticeable rounding errors in models I saw that I've never really noticed before. Need for Speed 3 also ran at good speed at 1600x1200 32-bit, but weirdly even though the geometry adjustment is perfectly fine on the desktop, there's a ton of overscan in NfS3 at the same resolution and refresh rate so I had to drop the vertical size down a lot.

Either way, good to know I don't have to worry about the monitor.