transplanting within first week of flower?

i flipped to 12 a few days ago and realized i should probably repot since its been a while in the 3gal !
thinking 5 gal?
any advise is welcome thanks

How tall are they and how tall do you want them to get?

about 1 1/2 - 2' lst'd but i dont want to get rootbound, theyve been in there for a long time and had one previous transplant.
do you think if i transplant from a 3 to a 5gal it would dramatically slow growth within the first week?

Firstly I would not transplant during flower ever. If this was my grow I would not be concerned especially if you LST'd. I use 3 gallon grow bags for all my girls and with the lst I have never had an issue. A good rule of thumb is 1 gallon of soil for every foot of plant. If they are in flower at that height, you should be ok in 3 gallons

I've learned that that rule of thumb doesn't seem to apply to a soilless mix for some reason, so I think it would depend on how much soil you are using to decide which bags you should work with. I usually veg in 1 gallon pots for 2-3 weeks, and then replant into 5 gallon pots for another 2 weeks and then flip. Tha t way I can water friday and not have to water over the weekend...

Go ahead and replant them IMO but try to imagine you're holding a human baby in the air upside down trying to it out of it's pants...be very delicate, or you may be flowering for awhile. I had to do this 5 days into flower a couple months ago with a mother I had finally flipped. She didn't flower late, so just be careful. Hope that helps!

i dont think ill transplant but maybe at some root start stuff