Adding salts to only the boil kettle?

This is my tap water. The mash pH of my pale ale grist is predicted to be 5.43. Can I restrict all of my salt additions to the boil kettle in order to adjust my ions and sufate/chloride ratio to the desired levels in order to keep my mash pH at 5.43?

Tap Water pH 7.7
Calcium 28
Magnesium 8
Sodium 5
Sulfate 21
Chloride 8
Bicarbonate 89
Cations 2.27
Anions 2.12
Tot Hardnes 103
Alkalinity 74
RA 49
SO4/Cl Ratio 2.6
Mash pH 5.43

No. If for no other reason that you don't have enough Calcium which has many important mash functions. Add enough Calcium salt(s) to the mash to get the Ca+ up to 50-75ppm.