Following my proposol, you could see any changes between different imports. Though we add/remove only some of the file, the commit will also track the differences between changed files. Creating a vendor branch on the first import and using a tag like VENDOR_1 and using new tags on this branch for following import (like VENDOR_2). All changes (new/rm and change) can be seen using "fossil diff --from VENDOR_1 --to VENDOR_2". As long, as we use the vendor branch only for the checkin's, we can also see them in the gui.

The import command is useful on OS != *nix. On windows, scripting these commands is a little bit tricky. Because add/extras can work recursiv, i think it's a good extension, to offer the mixed comman import.

I would always use multiple checkouts, to handle venddor imports - on the vendor branch - and development - main trunk or development branch.