I don't think you'll get many responses because there's no real need to us to experiment with different color profiles. IME BTAs aren't picky when it comes to spectrum, so I just use what I think looks the nicest to the eye.
I use AB+ at about 50% for my BTAs and gigantea on my 60 gallon flat and they seem happy, so I haven't felt the need to change anything. No BTA splits yet.
If want to encourage splits, I would do the typical tricks of the trade -- stressing them out with quick changes in temp or salinity or lots of feeding to get them to grow fast (and hope they split).