Hi Everyone,

There is a simple proof-of-concept implemented and hosted here https://andriianchestnykh.github.io/btc-safe-inherinance/. (I don't have good skills in Frontend development so far)
It works on Bitcoin testnet3. Even though mnemonics should not be exposed outside of a browser and will not operate with mainnet, still DON'T use mnemonics from real Bitcoin funds.

You can have some hands on experience with the inheritance schema discussed above by the following steps:

1) Generate two mnemonics somewhere (will probably add generation functionality here as well) and put into owner and heir mnemonic fields.
2) Get testnet bitcoins from some faucet into owner's address, which will appear once you input valid mnemonic.
3) Wait for the first faucet tx confirmation and click Refresh blockchain data button.
4) Now you can create signed transaction by clicking on Sign intermediate tx under every owner's utxo.
5) Transaction will not be broadcasted but just appear under Transactions column.
6) Now you can broadcast you transaction with Broadcast button. It will be broadcasted and new utxo appear under Intermediate addresses column.
7) Now you can either wait for 6 confirmations for the utxo in the intermediate address and withraw to heir or wait only one confirmation and withdraw to owner.

The PoC repo is here https://github.com/AndriianChestnykh/btc-safe-inherinance. Feel free to fork, change and test it locally. PR's with improvements and Github issues are welcome as well.

We are trying to figure out what can be done to increase chances for the industry adoption: BIP proposal, support libraries or services, etc. so please let me know if any ideas here.