As a user, I'd like the ability to tag by chapter for a series - tags tend to accumulate as a series continues, and aren't necessarily indicative of the content of the whole series when they do.
For example, the sexual violence tag on kemono jihen. (https://mangadex.org/title/20973/kemono-jihen) this tag only applies to an arc that's about 5 chapters long in the backstory of a side character. The tag _is_ appropriate for the arc, so it's not unjustified for the series, bit it is misleading.
Pairing this feature with a pre-chapter warning similar to the missing chapters dialog when a chapter contains content filtered in your preferences or outside of the tags of the series, and potentially with a spoilered justification for the tag to keep readers informed.
For example, the sexual violence tag on kemono jihen. (https://mangadex.org/title/20973/kemono-jihen) this tag only applies to an arc that's about 5 chapters long in the backstory of a side character. The tag _is_ appropriate for the arc, so it's not unjustified for the series, bit it is misleading.
Pairing this feature with a pre-chapter warning similar to the missing chapters dialog when a chapter contains content filtered in your preferences or outside of the tags of the series, and potentially with a spoilered justification for the tag to keep readers informed.