There’s a pretty big thread on making your own drinks: Make SIS BETA fuel yourself just a few pence per bottle
My personal concoction is granulated sugar + neutral hydration tab + a bit of lime cordial, as means I just need to order cheap tabs every now and then, and otherwise easy to source nearly anywhere. Find it very palatable.
On health aspects, I think a lot of advice is around sedentary consumption, in which case sugars aren’t going to be great to have in quantity. Sucrose (table sugar) is definitely bad for the teeth in a way worse than other sugars though (The Role of Sucrose in Cariogenic Dental Biofilm Formation—New Insight - PMC) so I’d always rinse with fresh water after a swig. I should probably just switch to malto/fructose…