Prettier 3.1 introduced experimentalTernaries, an opt-in formatting style for conditional expressions. Instead of the traditional layout that puts ? and : at the start of continuation lines, it places the condition and the question mark together and indents the branches, which reads better for chains of nested ternaries.
It is off by default and is explicitly experimental, meaning the exact output may change between minor releases. That is the risk to weigh: turning it on in a large repository means a formatting-only diff now and possibly another one later.
Evaluate it on a branch by setting experimentalTernaries: true and running prettier --write ., then reading the diff in the files with the densest conditional logic. If the result is not clearly better for your code, leave it off. The related experimentalOperatorPosition option, added later, similarly moves binary operators to the start of continuation lines and carries the same stability caveat.