As soon at the temps fall below 100 I'm going to plant a small number of Justicia Americana / Waterwillow / Bassgrass in my pond. I'm curious if any other pond owners introduced this into their ponds on purpose, and what their take on this plant is. I've seen it growing as both a submerged and emergent plant...thoughts?

I've not used it personally, but the St of Kansas spent a year planting a lot of this in Cedar Bluff Res years ago. It followed the declining water levels as the lake went through quite a few years of drop-20-22ft worth.
There was an inflow event that raised the 7000ac impoundment (at full pool) about 15' and there are some small areas of it working it's way back into shallower water but it didn't take off like they had hoped. This is an extremely infertile lake, 17-19' vis during WAE egg take in April, 6-10' mid summer.

Snipe,

Do the zebra mussels at Cedar Bluff cause a significant portion of the fertility problem?

Yes... Plankton eating monsters, Phragmites explosion hasn't helped matters either.