This is one last Hail Mary before reporting the following as a bug. I'm rolling this over to this forum because the problem is still present in Affinity Photo 2.
But do please see this post in the Pre-V2 Archive of Affinity on Desktop Questions.
A brief summary:
I'm on a Windows 10, 64-bit machine, now running Version 2.2.1 of AP. When I first reported this problem on February 4, 2020, it was in Version 1.7.3.481 of AP.
The "Proof Profile" list in the Soft Proof adjustment layer continues to list icc files that were deleted from C:\Windows\System32\spool\drivers\color years ago thus.
This continues to be the case even after a restart of Affinity, and for that matter after a restart of the computer, and for that matter after having updated from AP1 to AP2.
To my knowledge, I never imported these ICC files into AP using the "Import ICC Profile..." function on the File menu.
I think I've been through all of the various AP files installed on my computer, but have not been able to find these "ghost" ICC profiles.
These "ghost" profiles actually work, i.e., selecting them changes the look of the image. So it's not just that they're still listed, it is that they are still active somehow...
I'm hoping the fact that this problem continues to exist even after having updated from AP1 to AP2 might set off some bells for someone...
Thanks in advance and happy shooting to all.