Powering the Kapex (or anything else) from the CT doesn't limit the power to what the lable says.
What limits the power is the size of the fuse for the outlet that the CT is plugged into. The lable is based on the most likely fuse and if that power is exceeded continuously the fuse will blow.
The CT itself cannot limit the power available so if the fuse isn't popping then you don't have a problem.
So if I connect the CT 36 to a 50 amp circuit breaker I can power something from the CT 36 which consumes 40 Amps or 4,800 Watts?
That's a bit overboard. That's a total load (including the Vac) of some 6Kw! The cabling isn't designed for so much current. At the very least, you'll probably overheat the spade connections in your plugs & sockets & possibly also the cable.
Worse is that you could possibly overheat & irreparably damage the auto on/off circuitry within.
Worst of all is that the excessive heat could cause a fire.
A total load of approx. 15 Amperes (@ 240 V), corrected for alternative voltages using Ohms' Law: say 3600 Watts @ 240V or 30A/3600 Watts @ 120V would be "safe" maxima.
Total load INCLUDES the vac too, meaning that the "accessory" load connected to the CT36 should not exceed 2400W/10A @ 240V or 2400W/20A @ 120V. Excessive loads will also invalidate your warranty.