Calcium, magnesium and phosphate are not really necessary, and considering they’re usually $20 AUD each, I personally wouldn’t bother. A TDS pen tests the total dissolved solids in the water, which includes those. Phosphates is the only one I would consider, as if you have phosphates that are too low or too high you may get an algae problem, but that’s really up to you. Generally, though, I would say you really don’t need to.
Good to hear they’re more active now. As shrimp are more sensitive, I generally tend to do 10-30% water changes, so just a bit of advice going into the future there.
Sounding good!