It is very interesting, Robert... I'm just learning and experimenting too.
As regards your 'forest grown' onions, the first thing I wondered is whether, somewhere in the far past, it could have been a natural habitat for them. Does wild garlic (ramps) grow in forest too?
We don't have wild alliums here of course, but quite a few of the forest flowers are in the lily family I believe... They seem to thrive among the tree roots - maybe because their roots are such a different type. And are happy to be fed by the trees' leaf litter....
In Spain, there are wild asparagus growing in the forest! This could never happen here, wrong kind of forest and not a rich soil.
Your onions sure look great!