I’d like to re-visit this request.
I often work someone with no coverage so they cannot spot themselves.
I confirm all their details to record the QSO so I am in a good position to spot them.
So, once recorded, I can re-edit the QSO and the Self-Spotting button is disabled at this point.
It seems to me that it would be fairly simple to enable this button as a Spot this Contact button. And taking all the details from the edit screen, I could spot the other OP instead of myself.
At the moment I need to re-enter this info into the POTA page or the SOTA/GMA website page to do it.