When you add a second audience to a flag rule, the Match dropdown defaults to "any". There's no way to change that default for a project.

In most of our experiments, extra audiences are meant to narrow the targeting - for example, a platform audience plus a minimum app version audience. With "any", the rule buckets everyone who matches either audience, so the experiment can reach users it was never meant for. It's easy to miss in review because the rule looks right at a glance.

What would help, in order of preference:
1. A project or environment setting for the default combinator, so we can set "all".
2. An option to require "all" (or a warning) when a rule with more than one audience is saved in a restricted environment like production.
3. At least a clearer warning in the UI when a rule uses "any" with more than one audience.

Today we work around it by checking rules after the fact, which only catches the mistake once the rule is live.