I've set up some custom lens, but it gives high priority to a site in it.
For example, if you have there a bunch of sites for Android apps with aptoide being listed, aptoide ends up overtaking everything. You don't get desired results without removing it. I suppose part of the reason may be that they use a lot of subdomains.
Also, could it make sense to slightly increase the max result pages to 3-4? 2 may be limiting, but more than 4 is indeed not helpful.