It is Echinodorus parviflorus tropica a small form sword it doesn't get much bigger than that for me. It was crowded before pushed up against the glass a few leaves have BBA on the tips but the twisting or what appears to be deformed leaves seem to be normal for me as the leaves get bigger.I hear you on the uprooting capabilities of BN. What is the smallish plant more or less dead center with the sword-like rounded leaves? It looks a bit unhappy, did you move them? Not trying to be critical, I just don't want to go through 37 pages & I'm curious.
What did you have before, I don't remember? Crypt parva spreads so slowly as do the "clovers" (marsilea). Dwarf hairgrass "Belem" is all the rage here, pretty & maybe a nice contrast, but I don't know just yet on maintenance (co2 soon for me to play with). Glosso can also look good with maybe less maintenance. Staurogyne, maybe not enough contrast/bigger leaves with all your a. petite. HC seems a pretty PITA to me, maybe HM too. Just brainstorming for my next tank incarnation, I'm sure you'll choose something cool & grow it well!
I've had Glosso, Marselia, C. parva, Monte Carlo, no interest in HC, HM or hairgrass too much of a pain for my liking.