Unfortunately it does not work. Here is what I tried:
1.) Downloaded "linux-x86_1.7.13_MyCrypto.AppImage" and launched it
2.) "How would you like to access your wallet?" --> clicked on "Mnemonic Phrase"
3.) Enter 12 words as "Mnemonic Phrase", "Passphrase" I left empty, then clicked "Choose address"
a) In the combo box at the top, I tried "Default (ETH)" --> None of the addresses displayed matches my original address
b) Tried the same with "Custom" -> "m/44'/60'/0'/0 --> None of the addresses displayed matches my original address
c) Tried the same with "Custom" -> "m/44'/60'/0" --> None of the addresses displayed matches my original address (interestingly, the addresses are different to b), so omitting the final "/0" seems to make a difference)
d) Tried the same with "Custom" -> "m/44'/0'/0'/0 --> None of the addresses displayed matches my original address
e) Tried the same with "Custom" -> "m/44'/0'/0" --> None of the addresses displayed matches my original address (interestingly, the addresses are different to d), so omitting the final "/0" seems to make a difference)
4.) Tried the same steps 3.) a) b) c) d) e), but this time, I entered the password of my original Atomic Wallet as "Passphrase" beforehand --> Same result, none of the addresses match (Note: Addresses are different to related ones from 3.) a)...e))
5.) Tried "Custom" = "m/0/0", "m/0'/0'", "m/0'/0'/0'/0" etc., but it won't let me choose any of these, the checkmark button for applying is grayed out for all of them.
Note: d) and e) I tried because I found it here: https://support.atomicwallet.io/article/146-list-of-derivation-paths (but I had to append a single quote character to the second last zero, otherwise MyCrypto would not have accepted it; this is all so confusing and/or messy):
m/44'/0'/0'/0/0
When I try the same thing by installing Atomic Wallet and entering the 12 words, it displays the correct original address under "ETH". And it is independent of the password which I enter after the 12 words here. I tried with different random passwords. The resulting ETH address is always the same. I understand that the password is only for storing the data on the local disk, it has nothing to do with the 12 word mnemonic phrase.
Now I am worried. It seems like the 12 words mnemonic phrase only works with Atomic Wallet, nothing else. So if Atomic is not available in the future for any reason and I need to restore my wallet, I will have no chance.
Can anyone help me? How can I restore my Atomic Wallet 12 words mnemonic phrase on another wallet (application)? Or is anything wrong with my assumption that the 12-word seed is meant to work universally, independent of the wallet (application)?