Yes, it's in the "to do" list. If you want to give it a try that's perfectly fine with me
For some combinations it already works that way, but it doesn't work if all the fields are in the Songs table.
A possible solution for this particular case would be to use a SQL filter that filters tracks which are in albums with at least 5 tracks (this would work best with album artists since there may be albums with 5 tracks but all from different artists).
Another partial solution is to also add |min tracks:5 to the Artist field. This will at least filter out those artists who don't have 5 tracks in all their albums combined.