I say keep them. As you wear them more often, your feet will ever so slightly sink into the cork bed. Shell cordovan does not stretch, but that sinking of the cork bed will make it feel as though it has stretched a little. That's been my experience with shells that felt a little snug out of the box. As it turns out, it's been those shoes that have felt a little snug early on, that have been the most comfortable over the long run. My calf LWBs felt awesome out of the box. Now they feel a little too big, but still pretty good.
Has anyone here had a similar experience?
Not exactly, but the bone on my on instep protrudes a little further than normal which sometimes causes a tight fit in normal 'D' width shoes (I love Barrie). I don't know if I would try this on shoes I paid full price for but I got a really great deal on a pair of shell AE's that were a little snug on the sides. I sprayed Kiwi shoe stretcher inside the shoes and then (this is where you're going to cringe) reversed my shoe trees (i.e. left tree in right shoe vice versa) and left them that way for the night. Fair warning, when I first put the trees in, the shoes didn't look good. It looked like I was destroying the shape and look. But I had nothing to lose as I couldn't return the shoes. Woke up the next norning and the shoes fit perfectly and look good as new. They are as comfortable as any non-commando Alden's in my rotation.
Again, I don't know if I would try this with a pair of $700 new boots but for exotics that you seem to really like, it may be something to consider.