So why use it if you don't even know you need it? Sounds like the same approach as the magic 5.2 stuff to me.
Burton salts are a mix of gypsum, calcium carbonate and epson salts. Honestly the idea of mixing this seems irrational to me. How do you know the exact amount you're using? You don't.
Download Brunwater. Get your "salts" seperately, input your water test result into brunwater and then figure out the right amount of each "salt" needed based upon the grist bill you are using. That's the only way to be accurate. Anything else is just a guess and you're just wasting your time.
If you're only going to guess then you may as well do nothing IMHO.
edit: I also agree with the post above regarding acidulated malt vs acid. I've found it works great and brunwater has input and calculations for it included in the spreadsheet.