I don't understand your question, but low light will not discourage water rooted cuttings. I root in clear containers all the time. Roots do seem to form better in the dark, though. Why not try both and find out?

I am rooting in a vermiculite/perlite/humus mix in the bottom half of two-liter bottles. Since the plastic is clear and lets light thru, does the root stop growing when it reaches the side of the bottle and its exposed to light? If so, does this force more roots out from the cutting, thereby creating a more substantial root ball?

I used to use clear Solo cups so I could see to know when I had roots. The rose roots sure didn't stop growing when they came in contact with light. Cuts in the side of a pot are to allow more air in and prevent circling of roots. Air pruning of roots is done by using bottomless pots set on wire.