The chaeto establishes surface area where pods can feed on microbenthic organisms, it pumps oxygen into the water, and it provides hiding places and niches for shelter, that's what the chaeto is for. its a slow grower, but some nitrogen uptake occurs after proteins are broken down by bacteria, held in solution as subproducts, then sequestered by plant growth in the refugium. Water changes do better for a tank than relying solely on chaeto export.
The more surface area for hiding, the less predation the pods will face but in turn these nooks and crannies are harder to clean and marine systems should not build up detritus
your pods are likely to be limited by not being fed enough than by direct predation from other invertebrates, hope this analysis helps. If you will provide places to hide, both ghosts and pods can live together just feed well enough that all of them are well fed but the water is changed regularly
