My current feelings (subject to change) are more on the "it's okay" side. However, I know that it's against the rules of Tapastic to have completely unrelated or just semi-related doodles in your comic. Based on Michaelson's comment somewhere on this, I've come up with an idea that's not too far into the gray area, and I would personally find more or less okay in a comic I was reading.
Bonus doodles/comics/illustrations with my main character giving a running commentary, and showing his face in between the panels. Given that my comic will be centered around seeing the main character's face a lot anyway, there's not much difference in content. Problems solved, right? I know others might not be quite as happy about this, but what I'm imagining should be tolerable and within regulations.