Shamir's Secret Sharing Scheme. How do I revert to a normal seed?

[PrivacyG]

I think I messed up with the way I generated one of my Hardware Wallet's seed.  I have only recently moved all my Trezor T holdings to a new seed and as far as I remember, now the default seed generation process is the Shamir scheme rather than the typical sheet of 12 words like a Ledger or Electrum generates.  I remember they allow you to switch in between the two, but I sticked to the Shamir.  After discussing in another topic I found out this is not as safe as it seems so I now have one question.  Is it possible to revert from a Shamir scheme to a typical 12 words seed?

[DaveF]

Unless something has changed since I played with it  back in 2020 you can't revert you have to reset and start again.
You should do that anyway, unless you can be 100% certain that enough of the secrets did not get out where people could recover your wallet.

-Dave

[PrivacyG]

All sheets sat only in my own hands ever since their generation.  If these can not be reverted, maybe other than moving on to a next seed the best shot is just storing them all together the same way I would store a 12 word one.

-
Regards,
PrivacyG

[dkbit98]

It is true that there are some flaws with Shamir Secret sharing scheme, especially single point of failure, but it is still fine to use it if done correctly.
You could always generate new account and just add passphrase for more simple way of protection, or use multisig if you like real security with more complexity.
Then send and move your coins to newly generated address.

Is it possible to revert from a Shamir scheme to a typical 12 words seed?

You might want to take a look at this Trezor's wiki page to find all information you need about Shamir Backup:
https://wiki.trezor.io/Shamir_Backup

[o_e_l_e_o]

I had a quick poke around their GitHub, and found this closed issue which does seem to confirm that it is not possible to convert between the two as DaveF has said: https://github.com/trezor/trezor-firmware/issues/2048

So your options are either to stick with your Shamir's wallet or move everything to a new wallet.

Just for interest, Electrum have implemented recovery for Trezor SLIP39 (Shamir's) seeds since the most recent version 4.1.5.