Yea... looks like your fill water is going to give you a natural tendency towards high CSI and scaling.
Can't really do anything about your CH. And your high TA is going to tend to drive your pH upwards. Once it hits a certain level, your CSI will get significantly high.
So, what they are telling you to do is to control your CSI by controlling your TA. By bringing down your TA, you will be lowering your pH. And the lower TA will reduce your pH drift. Your SWG and CO2 generator are having additional effects on your pH, which will probably make targetting your pH a little more difficult. (Though the two may cancel each other out to some degree).
It's not a recomendation that I would make, but at least I can somewhat understand the logic which would lead to the recomendation.
If it were me, I would try to turn it around: Target your pH to about 7.2, and don't worry about your TA. At this lower pH, risks of scaling would be very low. It would also cause your TA to naturally come down to a sweet spot.
I would also add boarates (optimizer... borax) to your water. That is going to provide a non-TA buffer for your pH, and should control your algae. This will mean that your SWG would work a little less, and your pH drift will be a little less.
After you get everything tuned in, you may find a slightly higher pH is easer to maintain, and may consider letting it drift upwards a bit to see if it's easier. But I personally like 7.2. That's the pH of tears, and chlorine is more effective there.
I think that if you could follow something along these lines, and learn about the chemistry a bit along the way that you will find maintenance much easier, and it will be a lot better for your pool.