so I’ll need to know that I can trust the “Full multitrack” search filter on the database!

If it’s “full multitrack”, it’s wrong. “Multitrack” is more precise, because we have no control on how the stems have been provided. I personally have at least one song in the making that is multitrack but has keys and drums on the same track. It’s multitrack, but one of the two tracks (probably keys) won’t cut out on error, for obvious reasons.