The documentation says:
"When the spam condition is run, it sets up a number of expansion
variables. Except for $spam_report, these variables are saved with the
received message so are available for use at delivery time."
https://www.exim.org/exim-html-current/doc/html/spec_html/ch-content_scanning_at_acl_time.html#SECID206
It seems that that "spam_action" isn't preserved either:
https://github.com/Exim/exim/blob/master/src/src/spool_out.c#L238
I'm I missing something, or is this just an omission from the docs?
Paul