I've found that nginx doesn't start properly on first boot, with the below error message.

Sat Oct 10 16:21:57 2020 daemon.err nginx_init: nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
Sat Oct 10 16:21:57 2020 daemon.err nginx_init: 2020/10/10 16:21:57 [emerg] 962#0: bind() to [fd6d:ebd:af31::1]:443 failed (99: Address not available)
Sat Oct 10 16:21:57 2020 daemon.err nginx_init: nginx: configuration file /etc/nginx/nginx.conf test failed
Sat Oct 10 16:21:57 2020 daemon.err nginx_init: NOT using conf file!
Sat Oct 10 16:21:57 2020 daemon.notice procd: /etc/rc.d/S80nginx: nginx_init: NOT using conf file!
Sat Oct 10 16:21:57 2020 daemon.notice procd: /etc/rc.d/S80nginx: show config to be used by: nginx -T -c '/etc/nginx/nginx.conf'

Bumping the startup order from default 80 to 95, placing it just after done, solves the issue, but I'm not loving it.

I imagine some parallel process perhaps isn't fast enough bringing up the interface for nginx to bind to. Now, is this just a limitation of the init system? Would my fix be considered a "proper" one? What else can I perhaps do instead?