Overall I think your whole post is a great proposed rules modification.
I’d adjust this part to say, “may hold a flipper up to prevent automatic ball searches and get the attention of a tournament official”.
In many situations the first ball search will address the situation with a fair and expected outcome so I think it’s better for the rules to only nudge the player towards holding the flipper up rather than instructing them to do it right away.
There are also situations where the player may feel that even the first ball search could lead to problems, so I didn’t want to propose an edit that implies the player can’t call a TD over until after the first ball search.
I also incorporated Joe’s suggestion of using “official” instead of TD. I think that’s a good change. (Though it is a bit of a non sequitur from the core topic of this thread.)
For my own off topic addition:
I’ve got it on my pinball todo list to try to make it easier to generate a full set of rules that’s based on the IFPAPA standard while incorporating improvements like this one. This edit is a good example because it doesn’t really change the substance of the rules but it does a great job of making the game more welcoming for players and TDs who haven’t encountered that situation before. It’d be nice to have it published outside of this forum, but minor tournament rules updates haven’t generally been adopted the IFPA (which I understand).
When I’m called over to a game as a TD and I notice that it’s already ball searching, the first thing I do is tell the player to hold up a flipper so they can catch me up on the whole situation before the game gets to “pinball missing”. Players can learn to hold up a flipper from a TD in that way, but if we incorporate it into published rules a few may learn it there too.