Yeah, I was going to say that I grew most everything in my Tanganyika tank. Any epiphyte plants like Anubias, Bolbitis, Java fern and such especially. I had luck with Vals, Crypts, and I've never had dwarf chain swords grow so fast as in that tank. I wouldn't assume that because hardness is beyond the care sheet recommendation that they won't grow, you pretty much have to just try different things and see how they do. This is going to be a sweet set up, can't wait to see how it progresses!
Nothing good happens fast in an ecosystem.