Only rework the webcomic if you're ABSOLUTELY dissatisfied. If it's so-so and it's still at the point that you can show it to people without banging your head on the wall of regret, then there's no need to. Move on, and focus on improving the future pages. It's okay to fix a panel or two on some pages if you really didn't like what it looked like (but not all pages).
I have to admit I did reworked The Angel with Black Wings before I posted it online because (1) my drawing back then really sucked and it was not something I am proud of showing online to a lot of people, (2) I didn't like the pacing it was a little fast and I'm getting a little stuck in the storyline back then. Good thing I've only drawn 25 pages. Although, I still have a couple of pages in my current version that I am not satisfied especially the first chapter since I started drawing the current version on 2014 but there's NO WAY I'll rework this again. I probably just gonna fix a panel or two on some pages but that's just about it.
Plus, it's fun to see the improvements it's like an evolution chart of your art.