Just my personal anecdote:
When I saw the tile of this thread I thought:
not for me, I never drink energy drinks. I can't tolerate the preservatives etc. they'd wipe me out.
Then I realised it is something I've done for years, and my ME/CFS doctor recommended too.
Low blood pressure runs in my family on my dad's side.
When I was a teen I first noticed that I was getting dizzy etc and assumed it was anemia but no.
I started taking half a tsp of salt in my palm and then washed down with water each day when I got home from school. I realised that my mother's high blood pressure meant we no longer put salt in our family dishes.
But first I'd taste a few grains on my finger:
If it tasted overwhelming, really salty, then I didn't need it.
If it tasted really good (I called it sweet but more because it tasted so good), then I needed it.
When living in India for a year as a kid, we used Gastrolote when we got the inevitable Delhi belly. It saved our lives, literally. But we learned you could just do a combo of salt and sugar at a pinch.
All I'm trying to say is that it doesn't have to be a magic formula,
although for us, being sensitive to things, keeping them balanced is easier than getting back there.
Whatever salt you have, to taste
Banana or kiwifruit sometime during the day (or whatever potassium works for you)
Water throughout the day, extra salt to taste (shouldn't taste salty, just refreshing, amounts will vary by need)
Remember magnesium if you need it (I have plenty in my diet but I also have chronic diarrhoea so I still supplement when crashing and it reduces muscle aches)
I think of it as the salt helping the water to stay put in your body - without salt, water just goes straight through.
Edited to add:
Just to be clear: I think this thread is awesome, and the detail really useful.
When I say not to worry about the exact amounts,
I just mean that the amount we need varies from day to day
And our personal ability to manage getting the right mix of electrolyte varies too
(Maybe the supermarket doesn't have it or maybe we just can't do it all today)
So, even if you can't get the perfect mix,
If you have low blood pressure or POTs without high BP
just shifting from water, to water with electrolyte = salts, is helpful.
However you do it.