Add-ons — tag-outs, walk-ons, entrances, sound support from the sides, etc. — are absolutely like salt. A tiny amount of it added to your show can enhance it and make it that much better. But add too much and you ruin the whole thing, and you can’t undo it.
You’ve oversalted your food at least once, right?
You’ve seen dozens of oversalted shows.
*this analogy didn’t originate with me; I heard it second-hand. It bears repeating. If you know who coined it, please let me know.