The days to maturity varies so much and for so many reason that it is useful in only one instance. It can help northern growers get a general idea of whether or not they have enough season for a particular variety. Lakota is from Canada and he only has a 90 day season, last frost to first frost. He has to be careful what varieties he grows or they won't mature to harvest before frost sets in. Days to Maturity as stated by GRIN can help in making that decision. To my knowledge, it has no other useful function, and even then, it's not 100%.
My VA and Burley were planted toward the end of April. They should have been harvested and cured by now, based on Days to Maturity, but the unusual amount of rain, the lack of sun due to overcast days, the soil compaction from so much rain, etc. has blown days to maturity figures right out the window. All I know is that when 50% of them show at least one flower i will top them and when the leaves show signs of ripeness, I will harvest them. In other words, they'll be ready when they are ready, regardless of what the stated days to maturity is.
Another example is the spare seedlings I kept in the trays to replace any dead seedlings in the fields. The seed were planted in the trays April 26. They are about a foot high, stems the size of pencils and very leggy. The roots are coming out the bottom of each cell. This is why days to Maturity starts when the seedlings are planted in the ground, rather than two months after the seed are planted. By the days to maturity, they should have been head high and harvested a long time ago. It's just not a reliable figure to be beneficial for any reason other than getting a general idea for season length.