In #Bitcoin, ownership is knowledge. You either know the keys or you don’t. There is no substitute for competence.
Teach your heirs how to Bitcoin. It is the only way for them to inherit.
Discussion
They can inherit quite simply by you giving your keys to them. And really this is no different from any other kind of money which you either have or you don't.
#Bitcoin is the world’s premier, programmable, value-transfer system. Don’t invent a bespoke key-transfer system of your own. Just transfer the Bitcoin directly to your competent, sovereign, key-holding heirs.