Milter-greylist

> Is it possible to use SPF in an ACL to over-ride other ACLs or
> increase the delay or overide lazyness?

Read the greylist.conf manpage.

> I don't want to bypass greylisting for SPF-compliant email.

See above. It seems silly to do so. I don't understand why you would want
to do that.
You could also compile a version without libspf ofcourse.

> I want to make sure that non-SPF-compliant email gets greylisted,
> especially if SPF fails hard.

If the spf test fails, you drop through to the next acl in line.

Seriously though, you should allow as much mail as you can without delay
if you can verify the sending party. If the spf record matches it is very
likely that the sending party is a normal mail server and you would get
the message anyways.

Cheers,

Seth