Thanks. Do you like Nunchuk ? I heard from them from Odell but don’t know the story behind them. Also from my understanding the difference with multi sig is that if I lose two keys out of Three i am done can I save the same key in different devices ?
Discussion
You've got a few things going on here. First, your seed phrase for each key should ALWAYS be backed up to a steel seed-plate, or something similar. It should never live on the device alone. Devices die and get corrupted or otherwise destroyed really easily.
If you have properly done the above, then you will have three devices and three seed-plates at minimum. You only ever need two of those six items, plus your wallet config file, to recover your funds. You have one device and both the other devices got destroyed, but you can find one of the seed-plates? You can access your coins.
Next, yes, you can have the same private key stored on more than one device. Doing so just creates more potential ways someone could get access to your funds, though, without providing meaningful protection against loosing your key, as compared with putting it on a seed-plate.
Forgot to mention: Yes, I like Nunchuk a lot. You can even connect it to your own node via Tor on mobile by using Orbot. Very handy.
For multi-sig setups where you have different keys held by different individuals, such as for an organization, Nunchuk can coordinate the signing remotely. Very powerful tool, IMO.