Any pH change from CYA addition is normally taken care of by the normal buffer effect of the bicarbonate in the water (TA) and by outgassing of CO2 so the addition of an additional alkaline matierial to raise pH is totally unnecessary and often counterproductive to keeping the pH stable.

It sounds like you used the pool calculator's ("effects of adding chemicals" section to figure this out and discovered one of the pitfalls of its use, it does not take into account the effects of buffers in the water and the rate of pH change vs the rate of outgassing of CO2 (which, since CYA is so slow dissolving tend to counteract each other nicely), and so on.

Basically, you are overthinking things and making pool care much more complicated than it really is. Also, with your Goldline SWCg you want to get your CYA up to 80 ppm and 4 lbs in an 8500 gal pool only gets you up to about 50- 60 ppm from 0. Give the CYA a week to dissolve, retest. and then add enough to get it up to 80 ppm, which, if you were truly at 0 ppm when you started, would be about another pound and a half by weight.