On the first day of this week, I topped the plants after the 5th node. 3 days later I switched to 12/12.
The reservoir wasn't quite empty yet, so I didn't fill it this week, but I probably will at the start of the next one.
Plants are growing quickly now, the yellowing in the BJ and NYC has also pretty much recovered, nutes seem to be fine at the moment. I fear they might grow taller than I'd like them to, but I guess we'll see. I just hope I don't have to put in the net this time, as I like to reserve the option of taking them out of the tent. I also bought an RO filter, which I am probably going to use the next time I fill the reservoir.