I just cloned current git and compiled it and I saw some glitching when doing hgr while in 80 column mode on the apple2e driver.

Just start up, interrupt the boot with CTRL+F12, PR#3, HGR, and then hitting enter repeatedly causes the text screen to scroll and while it's scrolling, there's a bunch of glitching. Once the scroll stops, the glitching disappears.

[Linked Image from i.imgur.com]