I do not have any expertise on the correct ingredients/ratios for electrolytes, but wanted to add a helpful tip.
Certain cocktails taste better with a bit of salt mixed in. Handling and dosing and mixing dry salt is a PITA for bartenders.
Some have instead made the salt into a concentrated saline solution with water, adding that in with an eyedropper or mini measuring spoon etc.
I think doing the same with whatever mix of electrolyte salts y’all come up with, is a good idea as well for both ease and consistency of dosing.