You're absolutely right. Another thing that doesn't get much air play is the height of the OTA. The higher the OTA (further it is from the fulcrum because really this is just a lever) the more "weight" and less capacity.
The guy on Ben's Astrophotography exceeds the weight limit of his mount and still gets great results. So as Jerry said, your mileage may vary and I also like what Kent said a while back on another thread..."I can't advise you to drive above the speed limit" or something to that effect.
Mounts: Explore Scientific IEXOS-100 w Celestron CG5 tripod, iOptron CEM 40
Scopes: Explore Scientific FCD-100 ED-102CF, Various Canon lenses, ZWO mini-guidescope, StarField 60mm guide-scope.
Camera: ASI120MM Mini (mono), Altair GPCAM 130
Control PC: Intel NUC
Loc: 44 -79