Ok - now that you are using OCLP, your Mac is booting with Open Core. It would be good for you to learn how Open Core's config.plist can be modified to disable SIP. When you modified the OC config.plist, SIP settings will be configured as desired at each boot.OK. As a whole, I'm not real familiar with SIP and what it controls. The main reason I've disabled it in the past was to make changes in the filesystem to parts it prohibits such as in system and other parts. Simply using sudo while SIP is on isn't enough it has to be disabled for full access to the filesystem, so that's the context I was asking in.
EDIT: In your Open Core config.plist, look for this: