@gopher.ny About Chromecast.
As noted elsewhere, most of my Chromecast devices quit working when I switched routers.
In messing around, I reset one that was busted back to a "reserved" IP address matching the one it had before. PRESTO! It started working again.
So, I'm a bit happier ATM, knowing what messed up my Chromecasts--namely, they get messed up when their IP Address changes, so they need a reserved IP.
Re-running discovery causes the devices to be re-created, which then breaks all the rules.
So, it really would be sweet if there was a a way in the "Beta" Chromecast app to "re-find" all the device IP addresses without recreating all the devices, etc. Some sort of "refresh the IPs".
Even better: when one "vanishes", maybe the app could try to hunt it down in the background?
In any case... it was helpful poking around at the "App's State" to see the IPs in there--that let me confirm I was setting them back properly (I had saved a list from my old router, just in case).
Thanks!