Need fast help!

Hello as a first time grower, I have lots of questions. I have read hours and done lots of research but what I found most importantly is that one person will say one thing and another will say something else. I am stuck now, I recently bought a clone in rockwool with very small white roots poking out of the edges of the rockwool cube. I transplanted it into a 5 gallon pot and It started drooping and me, being very impatient, I took it out of the soil and put it into a tall red solo cup. I watered it placed it under the light and it Perked back up. I did that Wednesday March 30th and today is April 3rd. I have noticed nice new growth ( i will attach pictures) but when i took out the plant to take pictures for another thread I am creating, I noticed that there is a little root trying to escape! I don't understand how this little guy grew so fast because when I put the rockool into the soil the roots were maybe 1-2 centimeters out ONLY, so I don't think it could be rootbound? I tried to be delicate and place the root back inside the drainage hole but I was scared to damage it so i left it. Im not sure if I already need to transplant it or what. Also I am only growing 1 plant and keeping it small. If you have any other questions about my grow or any information needed please let me know! and most importantly what should I do about the little root escaping?! Thanks!
PICTURES (the one with LED purple light was taken on day 1 March 30th and all the other pictures were taking April 3rd)>>>

Re the root escaping just try not to damage it. Also make sure the cups have adequate drainage, if your slashing it with a razor you can cut small rectangles out of the bottom sides and/or drill holes in the bottom of the cup. Upcan to a one to two gallon pot within a week and make sure your medium has adequate drainage. Once it's established in that pot upcan to a five.

Hi, so Im not really sure why I didn't think of that in the first place. I was able to make a slightly bigger opening and finesse the little root back in. I do still have a question about transferring in the future. My grow room is small and I am planning to train my plant more horizontally ( combo of LST & Scrog). Im not sure if i should transplant into 1,2,3 or 5 gallon pots and what will work with my grow room. Here is a link to my grow >>> https://www.rollitup.org/t/need-criticism-help.904953/

As I've heard said before, there are as many ways to grow as their are growers.