I know you said you are not worried about the drooping, but I am worried about you interrupting the dark period.
I think you are identifying the nodes correctly that are likely to turn into colas. But I’m not entirely sure how much they’ll continue to stretch as you’ve said nothing about what light cycle they are in, veg or flower light schedule periods?
If it is in the flowering light schedule, as I said the interruption of the dark period could be detrimental. In other words DON’T peek in during the dark period during the flowering light schedule.
If it is in the flowering light schedule, the length of time, days or weeks from when you first switched to the, say most commonly used for flowering, a 12/12 flowering light schedule, this would help with understanding how much more stretch you might get and if it would be ok to top or fim or not. If it is still in veg, fim or topping should be fine with certain training and pruning techniques.