How to block all managed rules but otherwise allow traffic?

[dangarthwaite]

If I set default_action to "block" all traffic is blocked - even traffic that doesn't match a managed rule. If I set default_action to "allow" all traffic is allowed - even traffic that does match a managed rule.

I see one closed issue related to this. I suspect the answer is that an additional custom "allow" rule with low priority must be created. What is the simplest way to accomplish that with this module?