Transplant or let em be?

Those pots are too small. transplant. if you do it right, you should not get any transplant shock. Looks like at least 2 weeks of vege growth remaining before it stops.

If you are very careful potting them up will cause them less stress than leaving them in smaller pots IMO. I would pot them up. I direct sow my autos.and my photoperiods on 5 gallons so I can just let them do their thing. Thinking about going up to 7 gallon though because my last autos filled the 5 gallons completely with 4 foot tall plants. I'm more of a photoperiod grower though

If you think that you plants can grow bigger - you can repot. - Prepare additional grow medium as close to existing in the pots as you can. - Make sure that grow medium in pots with plants is moist, but not too much. - Cut off old plastic pots in half. - You will end up with a plant in the "pot" but without plastic. - Just transplant it into newer pot without removing anything. - If you prune some side roots - no big deal.

You're stuck. Transplant at this stage is risky. I'd roll with it

Too late to repot them now, it won't change the outcome much and the risk of stressing them now that they are flowering is too high. Transplanting them 3-4 weeks ago would have been better. Just let them be.

If they are in flower better leave as it is. I personally did not one and guided many, but here i dont see what you would win. Plants are almost at max size, look happy , would not risk. Next time choose wide , not tall pots, canna root system is not one deep root, its almost same tree as above surface.