Unless you have stains, the acid wash is mostly just a way to wear your plaster out more quickly by dissolving some of it to make it brighter. If you do have stains, there's less damaging ways of getting rid of them in most cases, but they take some effort on the part of the owner. Re-plastering is expensive so most people prefer to make their plaster last. But I'm sensing that cost isn't much of an issue for you, having an app is important, and you'd prefer that the pool look nicer.
Based on the track record and the bizarre readings from the phin thingie, it's pretty clear that isn't working.
If I've got that right and cost is not a big deal but I didn't really want to get involved and look after the pool myself, here's what I'd do. I'd go for it and have it professionally drained and acid washed to pretty it up and get rid of the CYA. For automation, Hayward, Pentair and Jandy are all fine, but what matters is that you get the right components. Take a look at them online (browse the manuals) or at a pool store and see which screens you like better. If you already have a variable speed pump, consider sticking with that brand, or allow for the cost of a new variable speed pump. Then post here and you'll probably find an expert who can help you choose the right bits and bobs for that brand.
Some automation systems offer a bundled SWG as part of deal. Your current situation is likely worse for your pipes than anything in your future if you follow Trouble Free Pool Care. Given those numbers, I suspect you'll find that your salt level is almost as high right now as it would be with SWG. Low pH is the enemy of copper, most often caused by indiscriminate use of solid chlorine.
Get the test kit so you can control what happens, and hire a pool service to do what you want done. They can adjust the SWG setting and correct the pH. You can test yourself periodically as an audit of what they're doing, but you'll need to learn TFPC to know what will keep your pool water reliably trouble free. If you don't go SWG, they can put liquid chlorine in, and leave you a measured jug for each day with the right amount to add. Include whatever you want the pool service to do (e.g. empty skimmer), but at the very least require that they brush the pool walls and floor every other week during summer, or get a robotic cleaner to do that and leave it in the pool. They can clean it out when they come. Be clear that you're in control of water chemistry decisions from the outset. If you have any questions along the way, just ask here.
If the pool service is too much ongoing cost, you can do it all yourself as described in about an hour a week during swim season, and an hour a month in winter.
Have fun with your decisions!
