This is a bit semantic for me, and I think you end up nailing it at the end.
Ruminate and reflection as you are using them have always been the same for me, but that is because I grew up on a dairy farm (there were sheep too)…and I would sit and watch the cows and sheep chew their cud…which is a primary meaning of the word ruminate.
I did not know what the word was at the time, but it would amaze me that they would eat something, and then later, cough it up and then chew it…seemingly mindlessly (and that is the key)…all the while absorbing nutrients from it.
I made big progress when I finally understood being like a cow was a good thing!! lol