for VHF/UHF/SHF, 6m, EME etc operators it would be nice to have QTH locator database which shows known locators for a callsign. Perhaps in the "Details" window. I wouldn't recommend to put a locator automatically in the locator field because there are many stations who have more than one locator.
I'm currently managing the QTH locator database for Win-Test. It's a database containing mainly (but not only) stations and their locators in Europe and adjacent countries who are active in VHF/UHF/SHF contests. This could be a start for a CQRLOG locator database.