I found a way to get persistent maxed zoom out. I installed a program AutoHotkey and created a script with a loop to always press minus key, at least on 2.6 version.
You just need to install AutoHotkey, create a file with extension .ahk, and paste this script below:
$stop := 0
RControl:: $stop := 1
Double click on file, and
Just hold RCtrl (Right Control) and press RAlt (Right Alt) to start, and RCtrl (Right Control) to stop.
The program will be clicking "-" when you start the script 10 times per second.
I hope it helps.