% glazed south facing wall - point of diminishing returns

So I know that for a passive solar home the south face wall should have most of the glazing. Typically at least 35% should be glazed. However is their a point that having any higher a percentage of glazing does not result in any more significant solar gain?

I.E. If 70% glazed walls gets you x amount of heat, but 90% glazed walls only gets you maybe x.1 amount of heat

Knowing that even the best glazing is not as insulating as a wall, is their a 'sweet spot' of what % glazing you would need?

I've heard same percent glazing as your latitude. Which doesn't really make sense if you live at the north or south pole or the equator. Somewhere in the middle, however, it seems like a decent rule of thumb.

Passive solar homes by definition heat themselves .

There is no limit to how many windows you need to install.
The 35% figure suggests a minimum level to have to obtain any heat gain.

But coupled with the glazing, its important to have thermal mass inside to absorb and store the heat.