If your device is even close to the maximum duty cycle all day long, then it’s way over the TTN Fair Access Policy. And while the duty cycle limitations would indeed be enforced by the device, if the Fair Access Policy is ever enforced, then that would be done on the network server, out of your control.
Also, the duty cycle regulations define the maximum during a device’s peak usage, not an all day 24/7 maximum. If all of us would be using a duty cycle of 1% continuously, then even when transmissions magically somehow don’t collide and no downlinks are needed, the capacity would be as low as 100 devices per channel and SF.
So, for production devices stick to the limitations of the Fair Access Policy, or choose a different technology.