There’s no way to write a safe application where you need to know whether a channel is open without interacting with it.
The best way to do what you’re wanting to do is with two channels — one for the work and one to indicate a desire to change state (as well as the completion of that state change if that’s important).
Channels are cheap. Complex design overloading semantics isn’t.
[also]
<-time.After(1e9)
is a really confusing and non-obvious way to write
time.Sleep(time.Second)
Keep things simple and everyone (including you) can understand them.