I am not an anemone jockey myself, but are there any generalities you can make about the [HASHTAG]#BTA[/HASHTAG] being predominately from coastal waters versus deep water? That might suggest that you have a significantly lower blue content to your light and significantly more red content.
Or like most corals are they found at all depths and mostly all environments? If that's the case then I think you might be able to slant your light anyway you want.
In any event you should use a [HASHTAG]#lux[/HASHTAG] [HASHTAG]#meter[/HASHTAG] when setting up your lights for them.
I think I have mine at 15.5k or close to it. The reason I went with that is for aesthetic reasons and my maroon clowns still show up good under this color. As far as growth I can't say it's better than another kelvin because this is all I've ever ran but I will say my anemones seem to love it.