Are the PH benchmarks the same for farmhouse cheddar as compared to a traditional cheddar or stirred curd cheddar? How does adding ingredients such as jalapenos effect your target PH readings if at all?

I would guess it makes little dif, considering its added after the curding. Unless the recipe says other wise, I would consider the “cheddar” PH same for all.

pH are same for all processes

jalapeños , cumin , black papers are usually added to Gouda cheeses not cheddar, but any way they added before pressing, and they do not affect the cheese pH at all