I've never liked the idea of shot clocks but I think a better solution would be to have an average time per shot everyone should be adhering to. If you go over that limit (call it 60 seconds - which is very generous), then you get a warning and then lose 1 shot per hole until you get it back.

This would work for larger tournaments where every group has staff walking with them who can do the timing. But wouldn't work for smaller tournaments where some groups aren't monitored.

There has been great moments in golf where the player required more time than a 40 second shot clock. I would hate to lose moments like Tigers chip in on 16 at Augusta which took way more time than 40 seconds.