Well, I don't know about any other persons, but for me, the most and convenient way to safely keep my seed phrase has always been to write them down on a piece of paper and keep it in a place that is safe.
It is quite susceptible for a piece of paper to be used to store seed phrases.
Of course, you have to use other supporting methods to keep the paper safe and intact,
or you can use metal to record every seed phrase, so it won't disappear or fade.
That is the most common and earliest option to do, if that method you think is good.
Store in an airtight place such as Time Capsule which is made of stainless metal and can withstand any condition when stored anywhere.
I have never tried anything complicated as the idea op shared, but for me, I have seed phrase to most of my wallets written in multiple random notes of mine, what I do is, randomly include my seed phrases in between my notes, so that even if someone picks up that note and read, he or she won't notice anything like a seed phrase there, this is how I have manged to keep my seed phrases safe for several years now without worry.
Randomly storing it in the notes you have will also not provide the best security.
If the note is read or owned by someone else, then they can read it and when that person is also a crypto user, then solving the phrase is easy to do.
For modern backup tools, seed phrases are now available in quite a lot of types, you just need to choose which one is best in your opinion.
Like using Cryptosteel, Blockstream or printing your own seed phrase on metal using Blockmit.
Check out this list of
Seed Backup Solutions, you can compare which ones are the best.
https://thebitcoinhole.com/seed-backup