It's awesome that you're testing the parameters closely and trying to make the transition smooth for the new fish! However, alkalinity, calcium, and magnesium usually are only things that impact coral, so I wouldn't worry about matching them for acclimating a new fish. Instead, I would be more concerned with salinity, temperature, and for more sensitive fish, possibly pH. A lot of hobbyists even uses the plop and drop method with good success. If you'd want, you could do a 30-minute drip acclimation though which is a more gradual transition. Remember that with longer acclimations you risk the build of ammonia and low ox levels in the bag water. Best of luck with your new addition!