Not so perfect, in any event. Here's a snippet of a debugging session

  DB<1> $t = 'teach an old dog new tricks'

  DB<2> $t =~ s/(dog)/@{[ reverse($1) ]}/g

  DB<3> x $t
0  'teach an old dog new tricks'
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You'd have to do

$t =~ s/(dog)/@{[ scalar(reverse($1)) ]}/g
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