[zahlman]

> It's also totally valid to not use this feature and just fill the buffer with spaces at the beginning of your session instead; just know that in Vim it's not absolutely necessary.

I actually set up a script to fill a temp file with a page worth of some "background" character and then open it with a special vimrc (mostly oriented around making it so that mouse drags use visual-block mode regardless of what mode I was in before).