Right, that listing I wrote was just a sample process to illustrate an idea of how to approach this make and achieve more consistency. didn't mean to imply that this was your make. If you're developing a cheese and don't know exactly what to aim for, one approach is to make small batches (1 liter or so), and vary the parameters. For example, add vinegar in progressively increasing amounts to target pH changes of .1. So, for example, add until you are at 6.3 in one make, 6.2 in another, 6.1, etc. And then compare the results and do a sample to see what people like best. That will give you a starting point.
The traditional ricotta salata is made differently in Italy, so I don't have an exact starting point... maybe 5.6-5.9 pH, then heat milk? In the traditional method, they take that day's whey, and add in some milk... maybe 5% milk by volume, and a bit of salt (I think 1-2%?). Then they will start heating, and will add 1-5% yesterday's whey to help increase acidity and precipitate the proteins. Yesterday's whey usually will be somewhere around 60-80 Dornic by then, so rather acidic.
For the rest, I think you will get far along in consistency if you somehow standardize the press and salting. Like rotate everything every 15 mins, or use a pneumatic press, or something similar that pressed everything at once in the same way. The salting you can standardize by brining, or by being really careful on the amount for each one.