Yes, I read your previous post. If they're not evenly spaced, a train will have to wait at W4 Street. It's not like trains can't stop.
And if trains can run at 30 tph ( ), they most likely can run at 30.5. And with the switches issue, it somehow works at Rogers Junction and in the Bronx!
If even that is not possible, only one line needs to end service early, like the for example. The © can keep running until whenever.