Thanks for the long reply WB.

I tend to use a calcium dense food like cheese with spinach.

Imho how the items are prepared is key. At least for those without a hyper reaction. Fortunately I love romaine. My favorite lettuce.

Recently, when in need of a spinach like green, lettuces have been a good sub.

Again, imho, cooking certain foods makes it safe to eat...well, safer.
Like treating corn with lye.

Looks like another book to put on my list!!