Originally Posted by
Davet
Highly unlikely that part of the derailleur will bend, it’s a pretty beefy piece. The derailleur hanger, the part of the bike that the derailleur mounts to, will bend first.
+1. Personally I wouldn't worry about keeping a spare but this
MAY work if you ever needed one.
Wolf Tooth RoadLink Derailleur Hanger Extension – Wolf Tooth Components