I'm an amateur breeder, currently developing three strains of my own. I'm a beginner but I've done my homework. And I understand, your question was a good one.
All F1 crosses are unstable, any genetic expression can pop up from them be cause they are a soup of all genetic traits of both strains, no traits are bred for in an F1 cross, auto or photo. The only thing gained from a first generation auto-photo cross is the auto genes that will be expressed in later generations.
Super autos, ( F1 auto-photo ), MIGHT flower faster than its photo parent, but many do not. and sativa dominant super autos run 120-140 days...... some even longer! And most still need a 12/12 light cycle. You can start them, then return to a longer period, but then they may take even longer.
These crosses may be ok for some people, its a matter of choice. IMO, its not a way to get quality genetics.