i'm not the dr. but i know you should atleast transplant 2-3 times because it will help the roots stay healthy and avoid stagnant spots in the soil to develop over time.
I'd wait 3-4 week (depending on size) before going to a 3 gallon bucket and then to a 5 gallon bucket before flowering. just my thoughts, i could be mistaken but that's what i've done and they look happy