You state you are normal porosity, so I do know that the amount of PT's do not need to be as much compared to someone with high porosity. I have tried the GVP Joico K-Pac and the fact that MO is the second ingredient, I didn't find it to be as strong for protein compared to the Gelatine PT. Have you tried just doing a PT and not following with a DT?
Also, with the bolded quote, I am not sure about the relationship between salt spray and PT? Could you elaborate more?
The results of a PT usually give hair more elasticity to it. Also, when hair is wet, the hair isn't 'mushy' (usually a sign of OC'ing) or breaks easily when you pull a curl.