Another thing to look at is how leaky is your rv? I can put my generator under my slide and have zero CO inside.
I have tested the CO levels of both my newest detector and my generator in a closed area, which is a single stall garage. On startup, my Hondas emit enough CO to set off the gas tester, but when they warm up to operating temperature, I have to hold the gas tester nearly in the exhaust stream to set it off. I do not know how the knock off generators compare, I don't have any of them.
Edited to add: The gas tester I use is a Drager X-am 2500, if anyone was curious.