I think the characteristic interlocking time is in the seconds, while the time needed for trains to clear conflicting paths can be in the minutes. But when the path conflicts only concerns a crossing, reducing interlocking time would indeed help.

On the open line, of course a moving block system would help. (On commuter lines with a low number of train types, it is easier to implement, see the success of CBTC vs. the not even in pilot stage ETCS Level 3.)

_{*Lunatic*, n.
One whose delusions are out of fashion.}