Prevent duplicate cron entries as well as prevent "too fast" settings

Right now one of my servers is having 100+ instances of the same cron schedule from different users. As you guessed, this causes high load when cron starts to run them. I think cpanel should have a feature that prevents users from setting a cron schedule if another user has already set it.

Additionally, it would be nice if cpanel can disallow certain "too fast" schedules from being set (e.g., every minute, every 2, 3 , 5, etc. can be disallowed by admin).