Day 58 flowering, I have limited time left, should I switch lights to 13/11 or 14/10?

I wouldn’t switch to 13/11 or 14/10 this late. More light hours won’t compress another couple weeks of biological maturation into those 12 days, and with unknown/bagseed genetics I wouldn’t introduce a flowering-risk variable now. Keep 12/12 and maintain a sensible DLI. They already look well into late flower and nicely stacked. Since day 70 is a hard deadline, I’d concentrate on keeping temperature/RH stable and checking calyx trichomes as you approach it. If they’re not fully where you want them on day 70, I’d rather harvest slightly early than mess with the photoperiod trying to force the finish.

you could but it won't make any diffrence you can notice. It'd be more helpful if for some reason you weren't providing as much DLI as dictated by local environmental factors, but that would be odd... more likely it'd be giving ~8.33-16.67% too much (1-2 hours more relative to 12) if you had it dialed in properly before. it's not about hours.. it's about DLI. There's a ceiling and there's no reason to push beyond that except to waste electricity and maybe even damage the plants. Plants can mitigate some excess light, but it doesn't make use of that excess. Atmospheric co2 and effects of temp/rh on metabolism will dictate the ceiling. Can't force feed it. 14/10 risks re-vege in more than a small percentage of plants... 13/11 might cause revege in 5-10% of plants? I'd say the risk is low for 13/11 but still possible. No need to do this. 12 days should be enough or close enough... better to give yourself more room for error on such things. 70 days will cover most but not all plants.

yeah dude go for it. I been experimenting with reducing the light cycle late frow. its not much effort and can really help to mimic nature. Its not going to make a 16 week plant finish in 10 or anything but . can help shave a week or so off in some cases. I would like to experent with a more gradual change late veg like outdoors, instead of the hard 12/12 flip. Helps to have some consistency and i haven had mental capacity to go that far with it yet. I may soon though

what do the trichomes look like? If your that desperate for space, as long as there is some cloudy you will get some affects from it but greatly reduced cannabinoid profile so not recommended. If it's legal where you live take them outside just during the day, no rain though. But of course she smell up the whole place when you bring her back in for the night. Nights in my area are to humid for end of flower

Stay at 12/12, you could drop the lamp down closer to the plant, just make sure to keep the average temps at canopy level below 27 degrees 👍🏻

Keep everything as it is changing stuff in the last 12 days won't do much anyway. More likely to slow things down. Enjoy the smoke, your early at the end tbh

Leave the lights at 12/12. You’ll not speed up any bud progress at this point, but if your not careful you could start them foxtailing or even reveging in the next 12 days.

11 light and 13 dark will get them to finish up much more decisively. Leaving them at 12/12 will max out flowering time. I have done 11/13 with landrace Sativas before and it works well.

It won't do much if you have enough light at 12/12. At this point in flower you can even switch to 18/6 without reveg/hermie issues, it's an old timer trick to start vegging the next grow earlier :)