Excellent post as always DWF.
To add a thought with regards to the stitching, no worries there. That thread wears like iron and will likely be stronger than the sole.
To be fair, we don't know for certain that any of those things caused this problem.
What we can say for certain is that cheese nipping will get you every time. One way or the other.
I'll have my cobbler take a look what the exact issue is when I'll take them to him for a full resole this weekend. I'll ask him to take pictures of the welt when the sole has come off.
A resoling job fixed the issue. The shoes are gemmed the cobbler told me, disappointing for a Grenson Rose shoe. The gemming hadn't slipped, it was still fixed to the insole. So it was just a weird bent in the outsole it seems, probably due to the gait of the previous owner.
No reason to be disappointed that Grenson Rose is gemmed. Of course they are. Nearly all goodyear welted shoes are gemmed. Including those that are more expensive than Grenson Rose.
Despite all the negative talk about gemmed shoes it is nearly impossible to avoid.
Vass being one of the notable examples of a non gemmed shoe for under a 1000 dollars.
Your new soles look nice - you sprung for JR - good leather!