Hey ChokDK.
If I get you correctly I have Undo function in jLight 1.5.x series. Now it's in archive but you can check it. Because It would be nice to have that in 3.0.
joomladmin.pl/archive/jLight_1.5.25_EN.zip
You can for example, open Global Config and try to change something. Changes will be marked and undo button will appear, allowing to step by step shift back to old settings.
Ctrl+Undo button should back All changes at once, but I don't remember if that feature is include in this version. You need to check.
This cool feature was added by Piotr (
piotr.cz/) to jLight distribution.