I guess nobody went this direction before...

Would you say that simply increasing all measurements in the plan by 20 percent (except the thickness of the building material) would bring:
(a) uneven and unpredictable results
(b) behavior of the cabinets very similar acoustically to the smaller one
(c) N/A - you recommend not to do this.

Thanks for your opinion.
Peter

Thanks, Dan. Your answer is helpful to an enthusiast newbie like myself.

As for the driver used in the original HDT, I just assume it is this one:
https://www.decware.com/newsite/DFR8.htm

with QES=0.23 and VAS=54 ltrs.

I am trying to get a feel for what to expect in case of bad synergy between the driver and the cabinet - peaks in frequency spectrum? Poor soundstage? Would the potential drawbacks be something that can be fixed with some experimentation (longer or shorter pipes, damping) or would the problems be beyond repair?

I am curious about "audio nirvana" sound instead of "fostex" sound - even though I had built my own Metronomes using Fostex 4.5" eNabled drivers and enjoy the results. I can see why Fostex was chosen as the default driver for HDT. The thing is I wish to try to build 10" fullranger and AN drivers get good reviews from those willing to work to achieve synergy with the cabinet.

Obviously, if there is just too much risk involved that AN in HDT would be unlistenable no matter how much tweaking, then it is better to invest energy in other designs... This is my dilemma and - when I am done with the building - other people might benefit from direct report on this combination.