I wonder if it would be possible to implement one of those roller filters? Like the Clarisea? I'm unsure if it would hook over the side though since pre-fab acrylic sumps tend to have the lip on them. So, maybe it wouldn't work, as the water level would be too deep to just set it in the sump.You might have some options available to include mechanical filtration.
Are you able to install a free-standing rack that could implement filter socks? Or is there enough space to include a filter media tray? Is there the possibility of using AquaMesh?
If you want to post a photo of the sump layout for better reference, I might have some more options.
With my experience with leopard wrasses, once they start eating prepared foods, they won't have to depend on a pod population for nutrition. I have had great results with using the LRS Frenzy Blends. My Blue Star Leopard ate it with gusto; and even would eat nori. And the little Ornate Leopard Wrasse ate LRS Fish Frenzy the first day she came out. Sure, pods would be nice but I don't think they're vital to the diet of a wrasse that is eating prepared foods.
