If you're going to do it for the inheritance of your chosen immediate family member, I wouldn't make it too complicated for them.
I'll just write down the seeds/recover phrases or private keys and then have those instructions on how to retrieve it. Every detail will be in there and I'll just trust them that they shouldn't open that treasure chest where these keys and instructions are placed on.
It's a matter of trust for me and I know that it's hard to trust that to anybody but your best option is to just put that trust to your immediate family, mom, dad, bro/sis, wife or your own child.
The only problem I have with this is that I am NOT confident they could keep it secure from other people on one hand, or remember the password on the other hand...
That's why my solution requires no need for passwords and is useless to anyone else who finds it.
I am sure that they use smartphones and has got passwords for their socials. That's like the basic requirement that you can have them for teaching about these technical stuff.
So that inconfidence of yours for entrusting them with these can be gone if you're going to teach them little by little until they are already familiarize with how the process does.
Anyway, there have been a lot of suggestions that were given to you and you can try all of those until what works for you well.
Also, when you reply to different people, you can just merge them in one post as replying consecutively is likely going to make your posts deleted or any other consequence decided by mod as we've got this rule;
32. Posting multiple posts in a row (excluding bumps and reserved posts by the thread starter) is not allowed.