I understand that this is a substitution, but the introduction of 44 new symbols is inconvenient for users. 
In fact, I currently use a credit card-sized metal card, with a one-to-many substitution table on the card face, and then switch the substitution set through the rules I define, as long as the rules are kept secret, your plaintext will be safe no matter the ciphertext is displayed publicly, or the card face and ciphertext are displayed at the same time. FYI. 

 This is designed as a functional art piece not as a daily rider or main stack long term storage. I would not recommend anyone encrypt their long term savings to a painting on the wall.

I’d be interested to see what you are using though as I am always fascinated by practical ways of encrypting plain text seeds. 

 Basically, I use such a card to manage passwords. Of course, there is no problem in recording the seed words. You can even display the card and the cipher text publicly, and no one can restore the seed words. https://image.nostr.build/04ba7957788a84288b7ea4eb8927b102e0f4b9784dd8bcfadfbf9753b920035a.jpg