Scheel mentioned in 1968 (ROTOW) that BAT was "far less colorful than SPL but that the two were differentiated by meristics and not color patterns" and felt the two very closely related species forming a super-species complex restricted to a specific area.
Seegers later described KUZ from a BAT like fish from Makokou in Gabon that most certainly was more colorful than any BAT and had a different color pattern as well. Huber placed this as a synonym under BAT almost certainly because it would be premature to erect a new species without knowing more about other forms in the area; without the understanding of the level of variance and degree of polymorphism a sound judgment can not be made based in a small sample of a greater unknown. Meristics are close, but nor radically different and there was no DNA evidence at all. DNA testing is now (late 2014) underway and hopefully soon a clearer picture of Raddaella taxonomy will emerge.
KUZ is another story and has a green (the same green as A. spoorenbergi) band in the caudal peduncle never found in BAT/SPL. KUZ is found outside of the range of the BAT/SPL fish and with one exception in Southern Cameroon the ranges never overlap. DNA testing will tell if KUZ is just a highly colorful population or a species in its own right.
Some (how many?) populations of Raddaella produce offspring that are highly variable to the point where the offspring look like a completely different form of Raddaella.
JVDZ offered the opinion informally there may be two species here and partial hybridization explains the variability both in the range and in certain individuals. So, the questions aquarists can help answer is which strains of Raddaella breed true vs. those that show variability in the young. (pers. comms. Nov 2016)
Jouke Vdz said in Dec/2016 (FB) "No splendidum DNA yet sequenced, but samples present in RMCA Tervuren collection. Collier presented this tree in 2007.
"Raddaella consists of 3 different major phenotypes corresponding with the 3 described species and occurring in 3 disjunct areas, with very narrow strips where 2 species meet." - Jouke Van Der Zee
These three phenotypes of BAT are documented here.