And this is the problem. 700kdt are ridicules as BBs. Supertankers? Sure. BBs? No.
Under HG2 you need 711kdt to build a "Battle Cruiser" with MS T, J4, A6, Fac 9 Screens and then you only manage Armor 11 not 14 or 15.
For armor above 11 you must sacrifice Fac 9 missile bays for Fac 7 turrets. Fact of life. Fac 7 missiles are relatively useless. So why build the monstrosity if you can build in a Spinal Meson in a smaller hull? BBs are not based on tonnage, but rather weapon.
Just like Earth today BBs have no real place; it's a cruiser universe.
HG2 came about before the 3I setting. DGW never built an efficient capital ship conforming to their own published rules. No rule set to date has ever reconciled this.
The very idea of a Fleet composed of J4 capable ships (not riders and tenders) simply fails. BB Fleets can not exceed J3.
If we keep the setting (though why since none of the publishers do) we must need a new, workable, rule set. If we keep the rules so we all design accordingly the setting doesn't matter.
I like HG2 for it's simplicity. I agree with Hans that a stable, consistent, universe is desirable. Fix HG2 and keep it simple.
IMHO all other versions of Traveller after CT have over complicated things. There have been great ideas that could have augmented CT, not replaced it.
The wheel has been reinvented so many times it isn't round anymore.
Vladika. You just proved my point. Without tweaking (home rules) larger ships are not effective. I tweaked...