I had to do a bit of googling to figure out what you were talking about, but I'm glad I did. I'm not a mushroom guy at all.

Podzol isnt the best term for what you're describing, if I'm splitting hairs. What you're talking about (the gray horizon) is referred to as an eluvial (leached) horizon. All podzols have them, but not all soils that have eluvial horizons are podzols, if that makes sense.

Brunisolic/spodsolic orders, for instance, have subgroups that have eluvial horizons, but they don't meet the criteria of podzols. Similarly, Luvisols have eluvial horizons, but it's clay that's been leached out of the eluvial horizons rather than iron or organic acids like in podzols.

I know. Too much information. I'm a turbo nerd about this stuff, and like teaching people about it. Even if you take a small bit away, I'm a happy guy.