Timeshift-Backup on Nvme /run ore sda1

After a long time I installed EOS again and I feel comfortable with it.
I still have one question: If I install the script for BTRFS and timeshift - which is better:
snapshot on / or sda1?
On a first installation without Nvme, I see a selection of the previous snapshots in GRUB. When installing with ‘/’ on Nvme, GRUB only shows ‘snapshot’ once and I have no choice.

Could you please clarify, which script?

A new EndeavourOs install nowadays doesn’t need any script to setup btrfs or timeshift.

Just choose BTRFS (optionally with encryption) in the live installer and once you’ve booted into your new system, do the following.

To add timeshift snapshot automatically on updates and make them available in the grub boot menu, simply

  1. run
    yay -S timeshift timeshift-autosnap grub-btrfs --needed

  2. launch timeshift and set it up to use the BTRFS partition which inhabits the root subvolume (@)

“Better” doesn’t really matter here: For Timeshift to work correctly in btrfs-mode you’ll need to select the btrfs system disk which has the root subvolume (@) on it.
This will be the drive containing your /.
Your root subvolume could be on sda1 or any other btrfs partition (nvme or other), so “/ or sda1” doesn’t always make sense as this isn’t necessarily always an option.