OP:
Good decision replacing the junk dealership delivery tires that the manufacturers put on. Install quality LTE tires that meet or exceed your 6K lb axle ratings.
Did you know they put on the same lowest cost bidder tire on park models that never move after delivery to site that they put on highway coaches such as your?
The only "must" which has ever been proven in all the ST tire proponents rants regarding reg's is that the sum of the tires must or shall equal or exceed the axles ratings. PERIOD!
Everything else is personal conjecture, interpretation as well as smoke and mirrors.
The section 5.3.x of the highlighted reg pertains to the information that is mandated on the vehicle certification or compliance label. Section 5.3.1 pertains to the tire info and the conveniently deleted 5.3.2 pertains to the rim info.
In no way does this change the only "must" or "shall" mandate above in section 5.1.2 that the sum of the tires equals or exceeds the axle ratings.
And for everyone's benefit I have linked to the Canadian regs showing the exact same requirements since the motor vehicle regulations of our 2 countries are harmonized for ease of application and enforcement.
Link