In order to "white-out" a line don't you need to match the line weight as well? I always assumed this so I set up a row of white pens with weights that match my standard progression solely for this purpose. I know using white out exposes weaknesses either in my method or AC's clean-up but that's life. Happily I'm finding AC's clean-up approaching an acceptable point, so for most drawings I've adapted the "reverse drafting" technique of leaving S/Es linked and patching where necessary.
I use an off-white, light gray back ground. That way all lines show including white.
That said I generally agree with your wish. Pure white to pure black and visa versa, as long as the Automatic Pen Color Visibility Adjustment preference is selected. It would also be nice for invisible lines to somehow be optionally or temporarily displayed.
AC26 INT, M1 Mac, OS 13.2.1
Yes, you read that correctly, we are in the US but use the INT version, because the libraries are better.