Right now I keep them with fuelleburnis and labs and socolofis. and they completely ignore each other. Female flavus are drab and I think 4 female is not enough for controling the male's agressiveness.
I wanted to do demasoni and labs but i talked to some1 and they said wasnt a good idea because the labs would get bullied to death, so decided to maybe try the flavus instead but it sounds like that may not be the best thing either.
I am not experienced enough but I think
Labs are not aggressive and usually dems let them alone. In my tank dems chase each other and completely ignore the other inhabitants. In the case of male flavus that I have, it also ignores the dems and only fights with the male fuelleburni any time and any place.
Mixing labs and dems is possible and gives you a nice combination of colors but I love my flavus and prefer it to the common labs. Finally its your tank choose the fish that you like and hopefully your choice will be successful.
my problem is demonsoni is nasty males. I had 2 nasty males that fought with eachother, so I removed one. and now he schreded all the females. the labs do not eat as well as the demonsoni. the demonsoni are more agressive at feeding time.