You really need a functional medicine expert to get to the bottom of this sort of issue as most doctors are just trained to think about drugs and the different parts of the body in isolation. After all, there is a limited to what a GP can think about in 10 minutes. In the UK the only way to excess functional medicine is to go private, I don't know about other health systems. (Functional medicine doctors are GPs who have done a lot of additional training.)
I am in the United States, and under 65 years old (i.e. cannot use the government-run Medicare) and at my income level the only available medical system is private -- I run a small business and pay $1,200 per month for medical insurance for myself and my wife. The appointment that I had with the nephrologists (two of them, plus a student intern) lasted one and a quarter hours (!!). They quizzed me at great length about my diet, lifestyle, and all sorts of other things. The subsequent doctor's note that I can consult on line is very long and detailed. I was very surprised, and impressed.
They are keen for me to try the low-sodium diet, but they were very clear (both during the appointment, and in the subsequent write-up) that they are not optimistic it will solve my "high urine calcium" problem. They just think it is "worth a try." In fact they are rather puzzled. It could be that my issue is "idiopathic" (i.e. that there is something genetic about "me" that causes this high urine calcium) but they said if that were the case, I would have had kidney stones earlier in life (I am 60 years old).
The doctor's notes are also very frank about it being "very unlikely" that I could suffer kidney damage, or kidney disease, even if I continue to have the occasional kidney-stone episode. My kidney function is normal. Hence, my extreme reluctance to "medicate' the kidney-stone issue for the rest of my life, with a blood-pressure medication. Strangely enough, the docs seem to agree with me on this one.
What I do know is that my "kidney stone issue" began a scant three months after I went on a low-carb diet following my T2 diagnosis.