I find the most stressful factor for beani, is their own siblings, or other cichlids.
I grew out a group in a 150 gal, where the alpha would actively seek out less dominant siblings and either kill them directly, or thru intimidation. I ended up with a lone pair in the tank that spawned a few times until the male killed the female.
The only way to keep other sub-dominant siblings from death was to keep them in separate tanks, or divided with egg crate.
And he only way to keep the grow out fry of the spawns from killing each other was to choke the tank with plants, so lines of site where broken, and juvies could easily disappear.
I found if temps were low (mid to high 60sF) aggression seemed to be less deadly, and the pair spawned at temps of @ 68'F. This makes sense to me, as they are the most northerly endemic cichlid on the Pacific coast, where night time temps can be less than tropical.
If I were to try them again, I would not grow them out together. I would separate the tank into compartments, and provide places to hide in order to break line of site.
I sent juvies out and suggested this, and when the info was unheeded, I heard very few survived. Simple rock caves and normal hides seem to me to be insufficient, because of the alpha's seek and destroy attitude.
I also found them very susceptable to duck lips when kept at temps in the high 70s and low 80s.
Much like haitiensus, because they are usually the lone cichlid in their habitat, keeping them with any other cichlid, seems to lead to an early stress induced demise in all but the largest of tanks