quad boot MacBook Pro (Retina, 15-inch, Mid 2014) -- will 10.11.6 -> 10.12 affect boot/partitions/etc?

Possibly this question cannot be answered, or maybe it will be deemed an opinion...? But, I recently had a Windows 10 update that forced me to reinstall all 4 OSs and again set up the perfect balance of boot loaders I wanted (Debian is the first one - I am not using rEFInd anymore, nor want to). So. As it may be difficult to know what the upgrade does, can I protect this boot stuff on /dev/disk0s1 ? Would copying it (dd maybe?) and then replacing what is there be sufficient? Or would I also have to backup my gpt partition table (gdisk) too? Other things? I can provide other information if necessary, but here is a question I have yet to address about something else that contains a lot of info about my laptop: https://superuser.com/questions/1296542/out-of-the-blue-linux-mint-makes-the-unmount-and-mount-sounds/1297114#1297114 TIA!