From what folks in BC says (rv forums and commercial haulers forums) they have to register their trucks at a GVWR.......which may be the truck makers GVWR or up to the sum of the vehicle mfg axle ratings.
BC still uses the same "weight scales" regulation which says in part;
**The gross weight of any vehicle or combination of vehicles shall be the sum of the individual gross axle weights of all the axles of the vehicle or combination of vehicles.**
The best way to find out how much weight your vehicle can carry is to subtract the net weight of the vehicle from the GVWR
(located on the driver’s door post). The number remaining is
the maximum weight your vehicle can carry.
Some of the new gen 1/2 ton....3/4 ton gas vs diesel....350/3500 SRW with those high gvwr numbers gvwr based payloads can over load the trucks RAWR if its all used in the bed over the rear axle when we look at actual weight numbers.
And a F350srw owners with a 11500 lb gvwr and a 3686 lb payload sticker isn't any safer than the same exact/same mechanical specs F350srw with a 10000 gvwr carrying the same 3686 lb payload.
Lots of reasons a truck mfg gvwr doesn't tell a trucks actual load carrying story or thats its some how the safe method.