To the OP:
I don't know about other operations, but I suspect they are similar to ours. At FedEx, we have a HUD and EFVS on all our Boeing aircraft and MD-11s. This equipment has no affect on any CAT-2 or CAT-3 operations. Those are conducted using auto-land and most aircraft (absent MELs or other issues) are able to utilize the lowest published minimums down to 300/300/300 (75m/75m/75m) RVR. Flying these approaches is done the same whether the HUD/EFVS is used or not. Of course, there might be some enhanced SA on the part of the Captain (and FO using a repeater that's being installed), but that won't affect the outcome of the approach in terms of being able to land out of it.
The only benefits of the HUD/EFVS officially is on CAT-1 ILS and non-ILS approaches in the 50 US states, US territories and US military airports.
The planned use of EFVS allowed charted approach visibility minimums required to start an approach to be reduced to a lower "derived" value. For example, charted visibility requirements of 1 mile can be reduced to 5/8 of a mile.
If enhanced vision allows identification of the runway threshold and TDZ, it is allowable to continue to 100 feet above TDZE. At that point, it's required to identify the threshold, lights or markings of the threshold, TDZ or lights or markings of the TDZ using natural vision or a MAP must be executed. So the bottom line is that EFVS is really just a way to potentially get into a field that's only equipped with CAT-1 ILS and/or various forms of non-precision approaches (non-ILS approaches).
The other benefit involves use of the HUD (EFVS has no bearing) which allows a reduction in takeoff minimums for the Captain from 500 RVR to 300 RVR. This provision must be charted for the specific runway and there are only a handful of airports world-wide where this capability can be utilized.