The  scheme that makes the  simple stuff   unfeasibly large and bulky.

Speaking of inheritance itself. Split SEED phrase into SSS blobs using 2 of 3 scheme.  Encrypt each blob with your hardware based  pgp key (How the setup such keys is described here). Give one of the encrypted  blobs and   HW security key to your nominee.  Include one of the remaining  encrypted blobs into you legal will with  assigned   nominee as the lawful beneficiary under will. Instruct lawyer to hand this will to nominee after your passing.