Don't have the Storybook here with me, but I'm pretty sure a couple of them are used in Scenario 2, at least. In that case, they just blocked off openings that went nowhere, so not really a big deal.
Putting in spoiler tag just in case. The token is used in Scenario 2.
Spoiler (click to reveal)
In scenario two 18B is blocked off leading to 17B. It's a misprint in the storybook. The wall tile should be 17B instead of 18B. 18B is already in use.