it will have a smaller root system, both now and when it completely heals. It's possible you didnt cut or rip any roots digging it up, but not very likely. I think i wouild of just left it outside and the days lengthening to revert to veg, dont get me wrong, if it was in a container outside i'd bring it in to revert it. as for the damage you caused digging it up and that, I wouldnt really worry about it, your plant will recover, but it will need time and it might delay the reverting process while your plant does damage control. dont bother buying something, you dont need it and im kinda skeptical on if it really works, its probally just veg nutes w/some chemical/s or other they will claim speeds the process up. I forgot about the switch from flowering nutes back to veg nutes. but the new soil should be enough for a while 3-4 weeks sounds right to me, but im not your plant or watching it so It may be longer or shorter, but not by much. You did not completely ruin it or anything, even if you had taken off half the roots or more on accident it would recover, but while its doing that other growth would basically stop. So dont freak out if it looks like its doing nothing for a while, week tops is my guess.