Yeah, Blue/XLU were my endgame logistics before I tried ED Shipyard, but with a low ship cap of 30-40 the slots are far more important than the logistics profile, Imo at least. Yeah, sure, it also depends on the setup, wolf pack tactics needs more ship slots than capital/cruiser spam. Cherry from United Aurora Federation has like 40k storage capacity... But less crew compartments than Newfoundland from ED.
In short: I think the Bernard is fine the way it is, why should such a super Tanker with 2 integrated OX be viable earlier? Reducing the supply/fuel/crew requirements would make a bunch of "smaller" tankers kinda obsolete, at least far earlier in the game than necessary since I classify the Bernard as an endgame logistics ship by being slot efficient. I don't remember the stats but I think the XLU Super/Dreadnought tanker has more fuel capacity? But it lacks the 2 integrated OX, so...
Well, at least the XLU logistics giants can fight (yeah, Newfoundland can too, Bernard has like 6 or so small slots spread over the ship so it can't Imo).

But I'd rather not let my logistics ships fight, although the setup and philosophy of my fleet depends on my mood and the restrictions I set for the run.