CO detectors are inexpensive. My camper came with a combination propane/CO detector. In addition I bought a battery operated unit. I replace my CO, weather station, clock, and kitchen timer batteries at the start of every camping season.
My generator is in a compartment made for a generator with two cabinet doors and good ventilation. The compartment is metal lined and totally sealed from the camper interior. I did have a CO alarm go off once. The generator was running and the back entry door is nearby and was open. Now I make sure to close the door when the generator is running.
There is very minimal risk with a proper installation and good detectors.
