Why doesn't Meta Box have support for dynamic fields?
Have a Taxonomy field to select the taxonomy and then a Post field to select posts. That part is easy, now if I only want the posts available to be selected based on the term selected in the taxonomy field, well that is not possible in Meta Box.
Is this on the radar or should I switch back to ACF?
Can we get a feature request forum perhaps? Do you have a timeline of planned or in development features?
The post field also supports to show posts base on the taxonomy field's value by using the setting query_args and taxonomy parameters. But it will show posts by taxonomy on saving and reload the page that means, after the field taxonomy saves the value, not get the value on "live".
As your expectation, I'm going to create a feature request for the developer team to show posts after "live" get another field's value.