Well this is somewhat poor style, but you could say something like:

options => defined($hashref->{'options'}) || []
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How about a nice map though that only pulls out the defined elements in your hash?

map { defined $hash->{$_} ? ($_ => $hash->{$_}) : ()  } keys %$hash;
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The output then can be fed directly into param. This is limited too in that it assumes your hashkeys are identical to your fields (TMPL_VARS), but if you can live with that assumption it might work for you.

HTH