I think we need to look at an extreme example.

We have fluid that needs to be cooled single pass 50C to 5C. So we need a evaporation temp below 5C, say 0C

We could have then up to 50K of useful superheat available. Lets say 24K superheat as this practically in range of most compressors.

Will this give a better COP than say having a conventional 6K Sh, and does vary due to the refrigerant?

And if it is better, what effect does this have on the design of the evap heat exchanger.