CBN / harvesting late

hello. from what i hear the more and more you wait to harvest the more and more THC converts/degrades into CBN. im wondering if anyone ended up with plants that only had CBN,, because they harvested too late or intentionally tried to. i guess, what im wondering is, if you wait long enough, do literally all of the trichomes turn amber indicating 100% CBN? is it possible to wait too long and then the amber trichomes/CBN degrades into something else? i think im trying to gain a full understanding of what the trichomes progress from birth to death. it seems the easy to obtain info is they go from clear to milky to amber and most people try to harvest when its like 70/30 milky to amber, but it seems that is maybe only when the plant has reached possibly 75% of its lifespan. im wondering what happens during the rest of the plants life, during the last 25% of its life. what happens inside the trichomes? do they go 100% amber and then continue to degrade into having zero cannabinoids? has anyone accidentally let their plants die cause they were on vacation and came back to plants that lived their entire life through maturity up till death and then were curious enough to see what the flowers contained and sent in a sample to the lab? what did the results say? i guess that would be the best way to know what happens to trichomes when a plant lives its full life up till death is to get a COA showing what cannabinoids are present in dead flowers. or, have you smoked or made edibles with "dead" flowers? what was it like? thanks in advance