Yes, I’m doing that right now, deleted my post because I found the doc, boot to r/o snapshot with a writable folder to RAM seems awesome… No security issues leaving a snapshot r/w, or even the possibility to write a snapshot by mistake…
Edit: it’s working, successfully booted into a r/o snapshot. To fix the .path not working due to the .snapshots mountpoint missing, I I did something similar of the topic First experiment with installing on BTRFS, but instead of monitoring the path, the timer will trigger every 1st minute hourly…
btrfs-grub2.service
[Unit]
Description=Generating snapshots for grub menu
[Service]
Type=oneshot
ExecStart=grub-mkconfig -o /boot/grub/grub.cfg
[Install]
WantedBy=multi-user.target
btrfs-grub2.timer
[Unit]
Description=Timer for grub snapshots
Requires=systemd-timesyncd.service
After=systemd-timesyncd.service
[Timer]
OnCalendar=*-*-* *:01:00
Persistent=true
OnBootSec=3min
[Install]
WantedBy=timers.target