Darn it Red Five, I forgot about checking your numbers.
Full disclosure, I haven't played with the BP8 functions yet.
The perfect BP8 enclosure to me is 8 panels total, not including bracing. If you can optimize the 3 volumes where you can use the wood thickness as the ports' lengths, keep port velocity below 10m/s, and get a response from 20-80hz, then you got the BP8 equivalent to a single fold TH in construction.
Now that I think about it, a 7 panel BP4 would be nice too!
Sony XBR65x900e / STR-DN1080 / original PS4 / WOW! Ultra TV / Quantum Access Mini PC Stick w/Windows 10 / 8 x Rockville SPG88 8“ DJ PA Speakers / Dayton Audio SA1000 / Kicker 08S15L74 in a Tapped-Tapered Quarter Wave Tube (negative flare tapped horn).