So my general rule is when I see roots on the sides then it’s time to up pot. So if you can see that then you defiantly can up pot now.
A little trick is to take your container with the plant in it and fill the new pot with dirt all around the existing pot that has the plant in it. This leaves the absolute perfect hole that you can easily plop and drop your plant directly into it.
Also, now is the time to Apply Mykos to your roots. The beneficial fungi expand the roots reach 100x or more. I use Garden Xtreme Mykos when I transplant.
As far as the light goes, this really should be measured and not guessed. Download a PPFD app on your phone and get a reading at the plant. You should be around 350-400 PPFD for 18/6 light schedule. Then tune your intensity / heights of the light to get you into that range.
I hope this helps.