Just to be certain before replying, I just tried it after upgrading my T-10 power distributor to a class 7. Went through the mail slot of an Orbis Starport without a problem, though you do (still) have to line it up in the middle and hog the slot like an NPC Beluga!
In other news, I just experienced a "first" today -- got interdicted by an NPC pirate ...in a Type-10 Defender. LOL -- suffice it to say, attempting piracy in a ship that can barely turn around inside the orbital radius of Mercury, especially when flying without turrets, is
ill-advised. It did not go well for the pirate. ;-)