Yup, i have a MD609 in a pot on my balcony that is flowering since october 2015... If kept the right way, baccy will continue to flower, i collected literally thousands of seeds. If the weather keeps up (or If you keep the plant inside the house in cold weather) tobacco can flower almost endlessly. After a while, the seed pods turn brown and dry, that is the moment to hang in a very dry place for a few days, then break the pods and sift the seeds. Very simple... BUT storing the seeds so that they are viable for a long time is much more difficult! This involves low humidity, absence of light and low temps. I find it easier to buy seeds from a reputable source every year, and to re-grow my saved seeds every other year
Moving forward, this year I'm going to start storing my seeds in specimen aliquot tubes, get them all labeled up, tops off in an airtight container with desiccant packs until I'm heating the house in winter and humidity is gone, then cap them up and toss in the chest freezer.
I bought a set of strainers ...one is a 400 and other is 600 ( I want to say I got them from Uline ,Bob knows the company as he put me onto them), stack them so the smaller mesh is on the bottom,and place over a clean white 5 gallon bucket. Rub the dried pods between your hands vigorously , the seed will pass through the first one and get caught by the second , chaf goes through and into the bucket. Between varieties , shake and wipe the strainers clean . I store my seed in tiny ziplock bags ,put those in with some of those silica gel packs in a bigger ziplock bag.