It depends on your cheese. You have to hit the final calcium target (both bound colloidal and unbound), which you manage through three mechanisms:
- Calcium degradation before gellification through rennet
- Calcium degradation post gel, during the set time and scald/stir, and
- Calcium degradation post whey drain, before brining, as the acid develops
Each of these does different things, and has to do with the rate of degradation. For example, with milk before it forms a curd, the calcium in the micelles is readily broken down, because milk is colloidal and micelles can move about. After gellification, it's essentially up to the available acid, and with a moist curd, there's still decent acid movement. When you fuse, the curd is more dry, so there's not too much that the acid can break down, and the acidity doesn't do as much.
You can use these three measures as a type of dial to create specific families of cheese. The dials are almost identical for each family, because the acidity falls within a range. And the subtle differences make for the variances. For example, in the alpine/gruyere family, to make an alpkase, you would add rennet at around 6.55, and for a comte, it would be 6.5-6.6. Typically, you also match calcium with moisture level and maturation target, because high calcium cheeses need more time for flavor development. You wouldn't make a high calcium, very moist cheese that ages in 2 months, for example (actually you could, but with adjuncts, have to engineer the make)
Hope that helps. In terms of the starter, generally, yes, the wait time is very short when using bulk starter with continental and yellow cheeses. But not always, not for all cheeses.