Actually there is a patch to get php 5.6 with openssl 1.1 , maybe DirectAdmin can also use it. See:As far as I heard, it's using OpenSSL 1.1. Note that only PHP 7.x will work with it.
Sure, unofficial in the sense that php.net doesn't use them. But the deb.sury.org repo does use them, and the guy who maintains that repo (Ondřej Surý) also maintains the official Debian PHP packages. I do place some value/trust in that and do think it's worth looking into as a signifcant amount of people still use PHP 5.6. It's not EOL yet.I highly doubt that. These patches are unofficial.