per-domain recipient policy?

Hi,

I have a fedora37 amavisd system that's processing mail for a handful of
domains. One of the domains wants more of the bulk email like newsletters
and mailing lists to be delivered than the rest. How do I do this?

I can create an SA rule that triggers on the "Precedence" header,
which should probably be enough to get started, but how then do I trigger
amavisd to use that to allow that mail to be delivered?

It appears policy banks are more for IP addresses, correct? Perhaps I can
use @score_sender_maps but I don't know how to do it based on an SA rule or
something that doesn't depend on knowing the sending domain.

I have amavisd connected to postfix as the default transport. I don't
entirely understand the connection between $policy_bank, $interface_policy
and being able to send specific emails to different policies.

If I want to have domain1.com use my DOMAIN1 policy and domain2.com use my
DOMAIN2 policy, do I need to have separate postfix transports send only
mail for the respective domains to their respective ports defined by
$interface_policy?

I'm hoping someone can help me make sense of this - I've done hours and
hours of searching to understand the terse amavisd documentation.

Thanks for any ideas,
Alex