If you want to keep your TA at 60, you will need to do two things to be in better calcium carbonate saturation (assuming your pool is plaster/gunite, not vinyl). You need to get your CH higher to at least 400 ppm (500 ppm is OK as well) and you need to have your target pH be closer to 7.7 instead of 7.5.

Every pool is different and your higher CYA level and your higher salt level make your pool requirements for a lower TA different than other pools. Normally for SWG pools, especially those with the CYA in the 70-80 range, we don't go lower than about 80 in TA. But it's really just calcium carbonate balance so with higher CH and target pH one can go quite low in TA.

The only thing to remember is that with the lower TA you should be very careful about using acidic chemicals in your pool such as switching to Trichlor for chlorine or adding non-chlorine shock (which is acidic). The pH shifts won't be huge, but they will be larger than they otherwise would have been.

You might try out the lower TA briefly before increasing the CH (but do use a target pH of 7.7) because if it doesn't help you then there's no point in doing it and increasing your CH (since it's hard to reduce once you've increased it -- drain/refill is the main way to reduce it).

Richard