[botsapper]

Your boat tail project should try to also address the aft vortices caused by the tires. Even MetroMPG's elegant tail extension, as shown by the underside boattail vids, easily show the turbulences caused by them. Your boatail project should address these concerns & add tire spats to clean up up these disturbed flows. I tried to cleanly integrate them, look OEM & match them with the black colored finishes.
Underside vids, another observation...maybe another project but fully optimized belly pans could use full length strakes for better longtitudinal flow, front to back.
As for the modest tail, think of it as the 'Short-Tailed' (as in the famous Aerotech ST) version of the project. Your plan as the LT version.