Over wintering Sedirea?

[Pilot]

Ok guys-- you know I have an issue with my sedireas... mostly I like them way too much and have a hard time not buying them when I see them. However, I'm curious, what is a the cultural requirements for these plants when it comes to seasonal changes? For instance, Neos enjoy a "cooling off" period of dryer, colder temps. Since seds are japanese orchids, do they require the same cooling off and dryer periods?

ALSO:

How much fertilizer do these guys like? I ask because I keep stalling out my sed roots. My troubled minmaru-shima has been trying to grow new roots but then they turn dark brown to almost black and stop growing. It's infuriating, to be honest. I'm trying so hard to get these guys to be happy and most of them are but the minmaru-shima in question as well as daruma chabo will often stall out their roots. I fertilize "weakly weekly" but thoroughly soak/drench the plants in their sphag mounds between fertilizing. I'm having a hard time recognizing any predictable or repeatable conditions that cause the roots tips to stall. At first I thought maybe the moss was staying too wet for too long, but while one root stalls the one beside it will dive into the moss. Then I thought I was hitting the plants too hard with fertilizer so I stopped for a time and it continued to happen. I didn't dare continue on without ANY fertilizer so I brought it back and it some roots continued to stall.

I'm seriously considering transitioning these plants to SH when I see new roots if I can't figure this out. Really wanting some input here.

Even with these issues, the seds I do have, sans the troubled one, seem to have done really well, especially a minmaru I got from seed engei, which seems to be pushing the upper limits of size and number of leaves it can grow in one season! It put on four new leaves since I adopted it, the leaves are larger than a quarter.