Well my angle is that since it's a true weed and plant, it can use nutrients directly from the substrate.
It's able to handle a wide range of conditions, arguably wider than most any aquatic plant(Temp, salinity etc).
Seems growing this for the utility might prove more effective. Tang's might not gobble it, but.....
This plant is very good at water column nutrient removal, it's also a plant that can have the substrate dosed with iron etc, so it should be less trouble than some/most macro's, no sexual/melt down issues, nice looking etc.
Should do fine in Onyx sand and mulm nutrients from a main tank.
Nick, grab some and send it on up. I'll take some. Just got back from the Keys with a fair number of plants. Didn't even think to look for it since I found other macro goodies.
Regards,
Tom Barr