CAP_SYS_CHROOT is needed for openvpn hardening.
Restart=on-failure
# NM doesn't want systemd to kill its children for it
KillMode=process
-CapabilityBoundingSet=CAP_NET_ADMIN CAP_DAC_OVERRIDE CAP_NET_RAW CAP_NET_BIND_SERVICE CAP_SETGID CAP_SETUID CAP_SYS_MODULE CAP_AUDIT_WRITE CAP_KILL
+CapabilityBoundingSet=CAP_NET_ADMIN CAP_DAC_OVERRIDE CAP_NET_RAW CAP_NET_BIND_SERVICE CAP_SETGID CAP_SETUID CAP_SYS_MODULE CAP_AUDIT_WRITE CAP_KILL CAP_SYS_CHROOT
ProtectSystem=true
ProtectHome=read-only