I used SoapCalc first when I started soaping using HP, and had no difficulties. Being new, I was using only the default settings, which are considered 'full water' settings, and those work fine for HP.
When I started doing CP, I still used the default settings until I learned about changing to lye concentration. Around that same time I also started using the
lye calculator at Soapee.com more often than SoapCalc.
But I have used some of the others, and all of them (that I have used) when using the default settings work fine for HP, IMO. It's been so long since I used some of them, I went looking just now and see that both the Summer Bee Meadow and the MMS at the Sage calculators have been updated. I found them useful for some things, but more work than I wanted to do for most things.
As far as the difference in evaporation rates, I think after the soap starts curing there is none. Evaporation should occur at the same rate, I assume, based on environment and composition of the particular soaps. So if I make the same soap recipe in two batches, one HP and one CP, once the soaps are out of the molds, cut and on the curing racks, I would expect them to evaporate at approximately the same rate. The only difference I would foresee would be if one has less liquid by the time it is out of the mold.
I do believe I have read more than once, somewhere something about how to calculate or estimate water loss, but don't quite remember where that was. But you could test it out by doing a side-by-side experiment and weigh the soaps every week (or daily, if you prefer) until they stop loosing weight and see how the water loss rates compare.
ETA: Here are a couple of threads that address water loss rates during cure:
https://www.soapmakingforum.com/threads/cure-time.35831/
https://www.soapmakingforum.com/threads/degree-of-shrinkage-during-cure.34604/
https://www.soapmakingforum.com/threads/water-reduction-and-cure-times.38161/