I just spent some time looking into this because I also have an interest in doing the same thing. I came to the same conclusion that you have as far as removing and adding the filter for the post revision.
I do not see any way to do this on the initial save, only on your second save as you’ve suggested.
The only possibility I can see is to add a pre_post_update https://developer.wordpress.org/reference/hooks/pre_post_update/
In this filter, check the post type, or other data to see if it’s something that you don’t want to save a revision for. If it is then do.
remove_filter( 'post_updated', 'wp_save_post_revision' );
Not that this will happen before ACF has updated the fields. Then, just before you update the post do
add_action( 'post_updated', 'wp_save_post_revision' );
