It shouldn't be taking that long. I also find it interesting that it stalls on exactly the section (store directories) where I thought it would find your corruption.
Please close it and instead run the System Update Readiness Tool:
What is the System Update Readiness Tool?
That will take up to two hours to complete (usually much less though).
Then please post C:\Windows\Logs\CBS\CheckSUR.persist.log.
Thank you!
Richard