Understood - but, at least you have been forewarned by the man pages, that any changes you've made to /etc/rc are going to have to be carried forward, because after an upgrade, /etc/rc will be wiped and set to the operating system version.
I'm a basic novice when it comes to OpenBSD (But a huge fan), and that, in addition to discovering that you keep all the old versions of every library ever installed when upgrading, where two things that I had been taught - so I presume that the knowledge was universal.