I'll chime in on this too. If the choice is between the one relevant field vs. all fields, I'd choose just the one. But in a perfect world, I could see the usefulness of, for example, having a single list of names that draws from all name-related fields (i.e. Creator and Audience fields), but not from other non-relevant fields (Type, Collection, Box, Folder, etc.). However, I'm guessing that would be more trouble than it's worth.
Version 1.2 is really excellent, by the way. There are only two features I still need in Tropy to make it a fully functional tool for my work. First is this autocomplete feature in metadata fields (the time required for data entry is just too steep right now to be feasible). Second is the advanced search capacity you have mentioned (assuming this will allow us to search/filter out items based on criteria for multiple metadata fields and tags simultaneously).
My first book was written using a spit-and-duct-tape Tropy-like database I created over a decade ago. It was these two features that, despite its many other flaws, made it an indispensable tool. I literally could not have written the book without it. I have more thoughts on search functionality that I could put in a separate thread if you-all are interested in that sort of feedback.