Mine actually usually has okay uniformity everywhere except about an inch from the right edge (particularly 1/3rd of the way from the top) and the magnet trick doesn't fix it for me there.

I’ve heard this and tried and didn’t notice a difference. What’s supposed to happen here? I have the Marker Plus.

This has never worked for me. Sometimes it's more than 1 mm off.

I haven't heard this trick. I'll try it out!

Not for me.