The Crispin Colloquy

@bcFour , I see that your topline is not folded and I can't see any extra piece between the upper and the lining for reinforcing the topline. Aside from the heel discussion an hoisting above, is it possible that the topline is not strong enough or the seam did not hit the seam reinforcement tape and therefore stretched too much?

I suppose, however, I put them back on the last and the top line was still as tight as it was originally.

I was told it might also be because the instep of the last needs reducing.

Is there any way to tell if there is insufficient volume in the shoe lower down causing the foot to push out there against the upper, as @nickb1 suggested, and what needs doing about it?

Quick response...not necessarily even on topic:

If one uses a pedograph to take a footprint, one can usually see whether the foot has 'settled' or not, ie. whether more substance needs to be added in the waist and correspondingly taken off the top of the cone. Another instance where more (better) data helps.

It's all related and all interdependent...IMO.

For making pedograph images, I was recently recommended Podotrack foot impression paper by a West End shoemaker.
Here's a short video about it : https://www.youtube.com/watch?v=tt887kUxb38
It's available on the internet in single sheets or boxes of 100.

@PhilipB1 I've been using Podotrack too - they sent me a free box of samples. It's a convenient package.