I’d like to customize the magic link email (so subject, body, etc.) for different use cases.
I.e., we don’t want the body to always be the same.
Is there a way to do this?
The template for passwordless can be customized although it’s done differently than the other email templates. You can read the process at (Email Template Descriptions).
In conclusion, it’s possible to customize it, but the level of customization is limited by what is made available in terms of context (see the linked docs) so can’t say for sure if it will be enough for your specific use cases.