I don't know much about btrfs, but couldn't you just keep the same mountpoints?
I followed these instructions to do a "lustrate" install on top of my old Debian install. At the end, I reallly scrutinized the autogenerated hardware-configuration.nix, decided it was close enough to my old /etc/fstab, and bit the bullet with sudo reboot. It worked except for a small hiccup that I can't even remember the details of now.
What you're missing is that the response was out of proportion. If I park my car in a street sweeping zone, they don't cart me off to jail, they write a ticket.
I miss the old bloat-free technology (not the picture quality though). These days, software updates add latency to your volume adjustments until you buy a new TV.
Oh my god, why did they name it "Lubelogger"?