Thanks for this, help me a lot 
But since I already switch behavior of F1…F12 keys (following this post) using /etc/modprobe.d/hid_apple.conf the change didn’t persist between reboot, I guess GRUB take over 
Anyway, in my case the solution was to set this parameter with GRUB also using the following command:
sudo grubby --update-kernel=ALL --args="hid_apple.iso_layout=1"