Okay!
Some more progress just after posting! Making the previous post made me find a misspelling of:
crt /var/etc/openvpn_client0.cert;
Which should have been
cert /var/etc/openvpn_client0.cert;
Now when I fixed that I get this error instead…
Apr 19 17:00:05 openvpn[9203]: Options error: Unrecognized option or missing parameter(s) in /var/etc/openvpn_client0.conf:33: script-security (2.0.6)
Apr 19 17:00:05 openvpn[9203]: Use –help for more information.