For who else might be interested on adding custom registration fiedls, I found a plugin which seems to be this:
We've been using an Amazon SES plugin for mail. Recently got a message that we're using SES Signature v3 and we need to use v4. That plugin hasn't been updated since 2015.
Has anyone else solved this issue? Do we need to roll our own? Switch to a different service?
You might wanna see whether this plugin works for you
@pitaj hmm...looking more closely at this...updating the dependencies might do it. But if not, that one seems to use the Amazon published SDK so it should definitely work.