This sounds like a great feature, but I'm confused on this bit:
I wasn't aware that an override record had it's own FormID. I just checked in TESsnip, and it also displays the FormID of the record being overridden. Where would we find the "real" one?
I probably should have been more clear. (You likely know everything I'm about to say, but I just want to make sure I'm explaining myself).
Forms Ids are represented as 8 digit hex number, of the form xx000000. The 000000 part represents a unique number specifying the record. The xx part referes to where the record is coming from. Let's assume a mod has 2 masters. In this case, Form Ids starting with 00 are overriding records from the first master, Form Ids starting with 01 are overriding records from the second master, and Form Ids starting with 02 (or anything larger) are new records that aren't overriding anything.
Let's look at an example.
Anchorage.esm has a record with Form Id
0200452B; it's DLCAnchT51DisplayArmor01.
Anchorage.esm only has
Fallout3.esm as a master, so the 02 indicates that this is a new record, and not an override.
Unofficial Fallout 3 Path - Operation Anchorage.esp overrides this record. If you use FO3Edit to look at the record in
Unofficial Fallout 3 Path - Operation Anchorage.esp, you will be told that the Form Id is
0200452B. However, as
Unofficial Fallout 3 Path - Operation Anchorage.esp only has 2 masters, the 02 would imply that this is a new record, when it is clearly not. That's because
0200452B is not the "real" Form Id in
Unofficial Fallout 3 Path - Operation Anchorage.esp. If you use TESSnip to look at the record in
Unofficial Fallout 3 Path - Operation Anchorage.esp, you will see that the Form Id is actually
0100452B, meaning that it is on averride of a record from the file's second master (which is
Anchorage.esm). This is the "real" From Id.
Again, if you use CREditor to select critical records, you don't need to worry about any of this as it's taken care of for you. This is only a consideration if you want to define critical records by hand (which is a reasonable and not overly difficult task).
Hopefully I've answered your question. If you need further clarification, or have any other questions, let me know.