You are one harsh peer reviewer !
I should add that I have made many mozz with this milk and some others and overall, despite the problem with this batch, its behavior (absence of browning, no string formation, softening without really melting) is very similar to what I have observed before. I have never seen a mozz batch that come close to the behavior of this S+C batch. I don't really see what variable could allow to get to this result with HM. Moreover, this fits with I have read on effect of homogenization on melting.
But maybe there is something else? I would be very interested to read suggestions on what other variables could lead to the results observed with S+C but with HM.
PS: I have been to Orosi Valley a couple of years ago. Very nice !
I am curious to know how it is to make cheese in Costa Rica !