No problem. My fronts are also pretty calm. To be honest i had always read people commenting on no sharpies in the tanks and thought they were a bit overboard LOL. That is until i watched my alpha that time, freakish fast speed when they bolt around in there. I could hardly follow it with my eyes. By far one of the fastest moving cichlids i have ever seen, its so hard to believe it when they just hang so calmly in the tank LOL.
I would try to find some nice big rounded rocks to go in there, like you put in the tank for me that time. That would look really good too.
Your lace rock would be perfect for the mbuna you have, maybe some of the peacock tanks too.