Well said! Fully agree. It’s important that there is that crucial initial exposure for new items, but it’s also important to reward those tracks that go on to sell well.
To add to your proposal, a balance between new and old item groups is a great idea. I still think a 1-column results page would work just fine though, if nothing else to maintain consistency across all the marketplaces. The results page could feature the all the groups in one list.
In my view, 50% should be new tracks (close to the previous algorithm), 25% hot / trending tracks (less exposure as they will likely have reached the popular files list), and the remaining 25% for those select “hit” tracks that proved their ground.