You know, I didn't think about this, mainly because I only worked private IFT for about 3 months, and since then, it's only been 911 (and even in those three months, there was no exclusivity requirement ,as I worked at one place for a week before switching to a better paying crappy private IFT service). Many in the 911 service work FT for one agency and part time at others. I actually know several coordinators who spend 5 days in the office, and work a few nights or weekends on a truck to maintain clinical competency in a real, not simulated, environment.
In fact, if a company mandated a "do not compete contract " or said I couldn't work at another company while working for them, or couldn't work for any of their competitors (even if they had better pay, better pay, or better conditions) anytime in the future, as a condition of employment, than there is a high probability that I would pass on that job offer. Unless that are going to pay me in excess of 80,000 a year with no OT, than I might say they can buy my exclusivity for that price
But that's just me, and I know I am in a good enough position where I don't need to accept the first offer that is thrown at me, so your experience might be different.