Hm, well, I suspect that with HF it is primarily a structural consideration, then a field assembly consideration.
I assembled a 2-meter beam with 5 elements that used thru-boom elements but the stresses on that are significantly lower than they are on HF sized beams.
I don't know a whole lot about heat treating aluminum, but I would be concerned that welding might cause the temper of the aluminum to be compromised? Additionally, in a commercial antenna, how would you design it for shipping? Welded stubs that the elements telescope on/in and bolt thru? I don't think it would be an improvement worth the additional cost.
This would not be for any type of resale, just for me to use, mostly vhf and uhf
I have full access to anodizing and heat treating. all factors are not a worry, just wondering why while on my search for a few good designs i couldn't come across any that used this method.