I’ve got the same setup: 6384PG but inside a tube full of oil. 12S, VESC.
The results are the following (on a static bench test):
3prop Pacificmeister with NO duct: 22kg static thrust, 1940RPM, 3500W - Couldn’t get on the foil
3prop Pacificmeister WITH Duct: 24,8kg static thrust, 2230RPM, 3500W - Couldn"t get on the foil
Solas 7 1/4x 6" without modification, NO duct: 32kg static thrust, 1890RPM, 3500W
So more than 50% more power for the same static thrus, pretty impressive !
What Duct are you using (from what I’ve seen it’s not profiled ?).