If there is something wrong or broken in your mod, you update it.
If you have new content in your mod, you update it.
Minor bugfixes you edit for - the mod will work, but you need to prioritize what deserves an update and what can do with an edit. If people complain about the bug again after you've uploaded the edit to fix it, just tell them it's fixed. Same way ZAPT did it, to the best of my knowledge.