Change email template and sender address based on the client-id

Hi everyone,

we have a multi-tenant application that has different branding depending on the domain, however the user base is the same (single realm).
To implement this we have a separate login theme for each client-id and we use a different client-id in each branded frontend.
This works great except for reset password emails.
Is there a way (even with a custom SPI) to implement that feature? What providers should I extend? How do I replace those providers with my own?

Any help is really appreciated