What about the potential mineral leeching issue with RO? I use a RO filter and mix it with 30% glass bottled water, both for taste and in hopes of avoiding any potential issue with leeching. I searched a bit but found nothing useful on the topic.

What would be leeching and where?

Sounds like a massive waste and headache for basically no benefit.

The theory seems to be that the lack of minerals in RO water might serve to leech minerals from one's body. I think there's also some concern RO water might leech from cooking vessels and organic compounds in plastic tubing, etc.

I have no idea how real the risk is, and it all seems less risky than drinking unfiltered water in most areas.

But it's no headache for me to mix RO water with bottled spring water, since I prefer the flavor and it takes seconds.

to leech ~ to drain (from the animal) to leach ~ to lose soluble constituents

Haha. And I even changed it from leech to leach and back again. English defeats me again!

City water hasn’t been palatable in years, in a a lot of places.

It’s mostly down to infrastructure, the pipes, not the quality of water released.