That is not true and actually just the opposite. CBD degrades quicker than THC so for a true CBD plant you will want to harvest on time or even a bit early. As for your second question, I am not too sure about CBD autos, the problem right now with high CBD strains in general is repeatability. There are a lot of phenos out there that have the capability of being high(er) CBD but so far breeders have had a difficult time getting the phenos to repeat. Southern Humboldt Collective has a few isolated and CBD Crew has a few as well. All are photos though. My guess is we still have a few years before people begin working with autos to get a reliable CBD plant. Best of luck bro.