MacOS 10.14.6 update inactivates rEFInd
Not sure whether this fits here, but just a heads up:
On updating to the latest OS update the boot loader was gone, so I had to reinstall:
back to the guide, then the webpage (a bit dense), then download the latest installer.
Reboot in recovery mode, deactivate SIP (system integrity protection):
reboot in normal mode, open terminal, drag the file 'refind install' into the terminal window, press enter, enter system password
after installation is done, type:
sudo /usr/bin/csrutil enable
reboot to re-enable SIP, and hopefully to see the boot loader reappear.
This is normal behavior. Following a system update, macOS blesses the system partition as default boot volume. If you have not tried automate-eGPU EFI, give it a shot. I like it better as an EFI Boot loader.