You don't have to reset all settings. Simply fire up a demo from XF
https://xenforo.com/demo/
That's what I typically do, but, it would be nice if you hovered, let's say, "Enable Multi-quote" in ACP > Setup Options > Messages, it said something like "Default: On (Checked)" as a tooltip.
Otherwise, each time one of us questions ourselves on a default setting, we fire up a demo to get an answer which takes about 5 minutes, and who knows how much resources are used to host that 3-day demo on XF for a simple answer, as asking on the forum would take longer.
I'm fine with using a demo to get the answer, it just seems like abuse to an extent when default settings could be somehow displayed or incorporated within the admin panel as described.