This week went a lot better than last, although still not optimal. After last week's transplant they all did well, as you can see in the time lapse. They do all have one or more deformed leaves and a slight calcium deficiency but look otherwise healthy. Increased base water (RO+calmag) EC from 0.3 to 0.4, feeding 0.7EC in total.
At the end of the week, the root systems looked very well developed and I transplanted them into their final 5L pots. Decent so far.