Say you have a custom field on a record that sources from a list of values. If you updated that field on a record to a different value from that list, the change can be logged in System Notes. But, let's say you went to the list itself, and edited the value, that change wouldn't appear in the system notes of said record, right? Since you're not technically changing the referenced Internal ID of the list value, NS doesn't count that as a change to display in System Notes?

I would agree with this.

Trying to audit discrepancies is a pain in the rear when I have to look at system notes in two places.

I would imagine the entries in the system notes table are not actually joins to that list, just strings representing the value.

If you are doing a system notes search that gets results - you can probably include both in one spot