I like the idea of indexing the location, and think you should store them in the zeros. I’ve considered reserving a standard zero for this.
I’m about to free up categories 01-09 so you could use 01 Locations and then give each of them an ID. Allowing you to link to them from a note like so:
28.01 Holidays
Location: 01.13 Backup hard drive in the garage
– and now the backlinks at 01.13 will show you all the IDs that store a thing there.
This feels very graceful. I’ll do it for my own stuff as soon as I get time.