I say, unless there are glaring errors in typos or continuity, I would leave the first set of episodes alone for now. Once you've finished writing the full manuscript, you can do an editing pass. At which point if your beginning is significantly better, then you might update the first ten episodes to reflect the current edit, so that you may snag new readers with the improvements.
I began posting my webnovel nearly a year and a half ago. I'd say my first few episodes were updated with minor changes a few times since they first went live. But after quite a few editing passes of the full complete manuscript, I only updated the first episode to its current version.
I'm withholding the final polished draft from the site since I want some incentive for readers to purchase a proper self-published version that's been edited and professionally proofread.
