I think the way God Intended patterns to be defined for later use is

    qr/(?(DEFINE)
          (?<name>pattern)
        )/x
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Oh, hey. I didn't find that earlier because it seems to be misfiled under the (?(condition)yes-pattern|no-pattern) section but it goes on to answer my original question

From perlre:

/(?<NAME>(?&NAME_PAT))
 (?(DEFINE)
   (?<NAME_PAT>....)
 )/x
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Note that capture buffers matched inside of recursion are not accessible after the recursion returns, so the extra layer of capturing buffers is necessary. Thus $+{NAME_PAT} would not be defined even though $+{NAME} would be.