Problem was intermittent. From a cold start, gas would fire and cycle normally 2 or 3 times before quitting. After quitting, just the ignitor would glow and then cease glowing without fire. My understanding of the theory of operation suggested the flame sensor as it is a normally closed switch that shorts out the primary gas valve until it detectes the glowing ignitor and opens, thus activating the gas valve while the ignitor is still hot. I believed the gas solenoids would be the 2nd likely choice and for the price, decided it made sense to do those just in case. Users report dryer works better then ever, suggesting intermittent problem was ongoing, just less severe.
Note that a lot of the time cited was just watching the cycling to understanding what was happening. Changing the parts on my unit was very easy via the front access panel.