Absolutely nothing wrong with dispo weed. It's legal, accessible and gets the job done.
90% of dispensary products are Budweiser IMHO. Good, pretty stony stuff!
--- BUT ---
When is the last time a jar of dispo weed reached up and grabbed you by the nose?
My Wife knew when I was choosing a new jar this morning - from the living room. --- I prefer Single Malt to Budweiser...
I'm with Budz --- bring on the 16 week sativas!
edit - never addressed teh original question - "How far can ripeness be pushed?"
1. Try it. We've all sample early buds - why not run a plant till the buds look obviously over-ripe and see what YOU think?
You might start growing 20 week indicas!

2. If you're looking at the back of a seed pack while asking that - get a marker and cross off the flowering time.
My 8 week OG Kush ran 9 weeks before it looked "right", so not too bad....