Agreed, if one were to make a tower you could simply add another woofer as a .5 way to boost sensitivity, and reduce IMD on the upper woofer due to less boost required on the low end. Would be a nice little tower speaker for sure.
So update: I’m Still waiting for my calibrated mics to show up, unfortunately shipping by usps to nz has been halted. I need these calibrated mics to turn up so I can nail the crossover down, then tidy up the boards and finish the cabinets. The speakers will then likely be gifted as wedding presents. Just living with these speakers for the last weeks they do sound amazing but I feel they could be tilting up slightly more than my measurements would suggest. So still a bit of work to do before I donate to the forum and edit the first post with a final crossover design. I have managed to get a bend on the ports and lower the tuning, which really did help level out the bottom end and take away a bit of boom.
For my next project I’ve just had some 8” waveguides printed, and eagerly await the release of the 8” purifi woofer. Hoping to upsize this design done here to 8 inch.