The previous fixed positions had padding of 20px.

I needed to add a similar padding so things still looked the same. Also, padding in this case is actually pretty useful. We don't want fixed positions right against the video, but having an actual padding introduced in the plugin is annoying when you need to move between fixed and custom, so I just offset it. Custom doesn't need it as people can find their own offset from the video edge that looks good to them.

The reason it is not 20px, and instead 3% is because we scale, and 20px was fairly broken in the first place.

3% is about 20px in a resolution that looked good with 20px.