I've been foraging king boletes for years now, though mostly in the Colorado Rockies. In this instance the main differences I noticed were the light to dark brown reticulation on the stem which was present on both young and older specimens. The caps tended to be a reddish brown color and I didn't notice any particular staining underneath. I'm fairly confident these are king boletes but due to how different they look from what I'm used to, I am wondering as to whether this is a specific variant of b.edulis which I am not familiar with.