I've asked a question here
but it never got answered (probably because the original post got answered and I asked after) so here's a new post to try to get my answer on this topic.
If we want to only override "promo" placement with an experiment, we still have to re-define every other placements in the experiment? Or if we just keep the "All Other Case" to "No Offering" it will fallback on the targeting?
Not so long ago we used to have this, which was creating a fallback on targeting-defined placements. Re-defining all of them (not only the tested placements) seems very error-prone and cumbersome.

