I'm pretty certain the precision of the PCM reporting is one degree Celsius. The sensors will also have an accuracy rating which I would expect is on the order of 5%. So there's some wiggle room to say the least. If anyone is really worried about precise running temp then they should add a more precise sensor where appropriate.
In my testing on the Gen 1 cooling fan control algorithm, it showed a moderate ramp up of fan speed, with something like a 15% floor, ramp starts at roughly 200 degrees and rises to 60-ish% at 236 degrees. 239 degrees triggers max fan. Yes, there's a hard jump from one reading below 239 degrees. Turning on the A/C added roughly 40% to the fan duty cycle. From this I concluded that Ford considers anything under 239 degrees to be OK. This also matches the temp gauge. 236 degrees has the needle in the middle (just like at 200 degrees!), then at 239 the needle starts rising. And the rise isn't necessarily tied directly to the temp either. I think it's more to get attention. I didn't push much beyond 245 or so, as even idling that can get a little toasty.
Note that those readings are for the outlet pressure control from the pump. The resulting fan speed probably isn't a direct linear correlation.
IMO, if the system isn't loosing coolant, the fan/radiator can maintain a stable operating temp that the PCM considers acceptable, and there's not signs of running issues (pinging, low on power, seized engine), then I think it's operating within design parameters. These engines accept running hotter than engines from the 70's. I would be panicked if my Olds 403 ran over 200 degrees all the time, but it has a vastly different cooling system and cooling demands.