Yes to 76 days at “normal” operating temps but you can do 45 days if you raise the temp. (I don’t increase the temp when I fallow) I just do the time.
The dragonet is a bit of a gamble, put him in QT (how to we feed), leave in DT, may fall victim to the parasite. I don’t find the dragnet family to be very ick prone, they excrete a mucus at night that likely protects from ick attaching itself.
Worst case scenario is loss of fish, and restarting fallow day count.
Me, I would take the risk and keep him in, buts your fish.
Ghost feed during fallow, but very super tiny amount.
Very little bacteria in water, you can transfer any mature media you want, but after treatment, it’s trash.
With no media, have new temp matched saltwater available and change some either daily or twice daily while watching ammonia levels.
Feed them as much as they take, but, vacum up the missed food and stuff on the bottom of the QT.
There is no data on the effect of UV versus fallow time, it would be a complete guess. Nit