Ubuntu 26.04 + Btrfs: missing @ subvolumes

Question 1

The bounty expires in 5 days. Answers to this question are eligible for a +50 reputation bounty. codenoob is looking for a more detailed answer to this question:

I think that with BTRFS (and actually other 'recent' Linux features) there is lots of coverage but it's all either very board and not deep, or when deep is very narrow. This question gets to things about BTRFS that I have not seen answers to.

I’m testing Ubuntu 26.04 with Btrfs and noticed that the installer creates a flat Btrfs layout (no @ and @home subvolumes), unlike Kubuntu which sets them up by default.

This causes issues with tools like Timeshift that expect the standard @ layout.

Question:
Is there a supported or recommended way to install Ubuntu 26.04 with Btrfs using @ and @home subvolumes during installation (without manual post-install restructuring)?

Alternatively:

Is this behavior intentional in Ubuntu’s installer?
Are there plans to support a proper Btrfs subvolume layout like Kubuntu?
What is the best practice for users who want snapshot-based rollback (Timeshift/Snapper) on Ubuntu?

Any official guidance or recommended workflow would be appreciated.

Question 2

i did a search on google and this is what i find:

"Yes, the flat Btrfs layout (without @ and @home subvolumes) is the intentional default behavior of the modern Ubuntu desktop installer (Subiquity) since Ubuntu 24.04 LTS.Unlike the legacy Ubiquity installer or the Calamares installer used by flavors like Kubuntu, the current Ubuntu installer does not automatically provision these subvolumes during a custom partitioning phase, which directly impacts snapshot-based utilities like Timeshift."

As a solution? try this https://github.com/diogopessoa/ubuntu-btrfs-install