Photo period plants can be transplanted no problem in the veg cycle. You don’t want to be transplanting during flower. Some people actually suggest it is best to allow photoperiod plants to get a little bit root bound and transplant them on during veg rather than put them in a huge pot from the get go. The plants plants will grow larger if they have more root space.
Auto flowers... you don’t want to be transplanting ideally. This can trigger early flower and reduce plant size and yield.