Hey, totally sympathize. When you're working stuff supplied by others, and they do "interesting ... things, well ... yowza, that's a problem.
I've worked a couple projects that had to be outside my Production due to the issues of the client ... which had intriguing issues that caused major headaches. And even been queried to potentially take over couple projects, one of which sounded initially kinda glitzy cool.
But the lead producer had done much of his own setup/initial editing, and it was now down to try and find a way to take the hot mess he'd made, of this massive project for the total assets involved, and get a final edit/color/sound done. After a few questions, I politely said no. As in no way in Hades was I gonna touch that project.
I think in your case I'd sill use Media Browser to import the sequences into the project. Cleaner if slower workflow.
Not so far along in this one that I need to punt but it does make more work for me than I expected. Hopefully Adobe can work on this – certainly not a Resolve fanboy but I feel this would not be in issue. I wonder if there is some sort of work around RT'ing with Resolve but probably not.
**edit: unchecked "automatically hide depended clips" and now it works but brings in all the individual clips - which are already in my project, and orginized. Argh
Mod note: Moved your solution to the latest post so it can be marked as correct.