Lollipoping before flowering

U still have plenty nutrient issues to go into flower, fix them first.

I would not. Are you plants the same size as the youtuber? are you growing the same strain and doing the same style of growing as said youtuber? Lollipopping can be useful in a SCROG net when everything under the net is getting little to no light. can help airflow that regulates temps and RH. These plants are to small IMO and you will only set them back if you strip them.

You still have lots of growth that needs to happen before you should cut much.. by the time its ready to flower. All the leaves you see now will be what's need to be lollopped if that makes sense. ok at my current run of Green Poison and Tutankhamun. you can see i grew the plant to the first net. then i flipped to flower. The plant stretched twice the size, and that's when i removed the lower part of the canopy after it had been shaded out. Think of the plant as growing and your trimming will, "lock-in" the progress. if that makes any sense. If it were me I would veg them another week or two, but I understand if you want to do quick rounds, that's acceptable as well. but for smaller plants, i wouldn't do much . Id wait until after stretch phase of flower then remove anything that's touching soil ,causing airflow issues and just looks wimpy and sickly if any at all.