After reading Abigail-II's answer and tye's answer, I looked in perlvar for $^H and found something almost identical to tye's answer:
BEGIN { require strict; strict->import('vars') if $condition }
# which to import all restrictions would be
BEGIN { require strict; strict->import if $condition }

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In reply to Re: Triggering 'strict' from within a package by runrig
in thread Triggering 'strict' from within a package by kal

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