I like this idea. I have the low end covered for sure with the 2 Rels and the fathom. Dialing those all in just right really upgraded the whole setup. Unburdening the singles from carrying the lower stuff at all could be interesting if I can blend it all well.
Good suggestion. Crossed my mind to run separate tweeters a while back but I abandoned the concept thinking it would be hard to integrate well. I’m going to try it and see what happens. The Aperions look like a good option. I’m open to any other suggestions too. Haven’t shopped for separate tweeters since back in my car audio days