I am not familiar with the coinbase wallet. Do they allow sending coins to a legacy address?

A multisig output script encoded in base58chk is essentially the address.

BlueSlime

To be clear, this is not a question of reasonableness or security. You can set up a perfectly secure multisig wallet with the technology we have today.

This is purely about the user experience, and making it intuitive for a new person to understand. Bitcoin is complicated enough as it is, but it can be explained in extremely simple terms:

Your funds are stored at an address, which is a location on the Internet no different than the address that identifies the location of your house.

Your funds at the address are controlled by keys. And a key is represented by 12 words (or 24 if you choose).

In a single sig, you need only one key to unlock and move funds, but in a multisig, you can set it up so that you need 2 of 3 different keys. This provides redundancy in case you lose one. 

That’s it. And the user experience should match that, at least for the average consumer.

Cold storage is terrifying for most people, but it doesn’t need to be. And there’s no reason why people should be introduced to Bitcoin through exchanges, and only later taught to move the funds to cold storage.

You don’t truly learn about Bitcoin until you take it into your possession, and we should develop an outstanding user experience that matches that behavior.

Again, this isn’t about what’s reasonable to ask someone to do. The burden is on us to create the most beautiful, simplistic, and dare I say magical user experience that could possibly exist. Technology should be like magic, and Bitcoin should be no different.

"move to X then Y" doesn't sound like a dealbreaker for any reasonable person

Is your grandmother unreasonable?

If so, consider talking some sense into her

supertestnet

True. But the user experience for moving funds directly to a multisig in an output script is quite poor today. The entire industry is setup to move funds to addresses.

The user experience for my grandmother should be as seamless as possible. If she wants to move funds to and from Coinbase, she should be able to do that directly. To use a multisig output, she would need to type in an address on Coinbase, moving funds to a personal single sig, then make a transaction moving funds to a multisig output script.

josh

bitcoin

Can we make 2-of-3 Multisigs a better user experience? 

You don't really need to store the derivation path or the script if both follow a well known convention.

You also don't need to remember or inscribe the pubkeys if you do a multisig in the output script. Segwit is optional.