Not at all, I'm very open to the idea of doing Wabi Kusa submerged as well. Many of my customers have had great success with them submerged. I've got some amazing little Wabi Kusa bricks of HC and Glosso growing out.
You're giving me some ideas -- I just might flood this tank and use the Glosso bricks and these four Wabi Kusa as the only scaping materials. I'll make a poll.
Bed of clean pool filter sand. Those WK stacked just like that. And some little critters swarming about.
Maybe even regular Cherry Shrimp. Or wild-type Neos so they don't distract from the plants but still provide life and movement.
I know where I can get PFS. I'm going to use some glosso bricks in addition to just these balls though, so I can have a little horizontal action. I agree that wild neos would be great in here, let me know if you can hook me up!
This is going to be a fun project, a true "instant aquascape" in action!
"Simplicity is the ultimate sophistication." -- Steve Jobs