yeah but is electrum multi currency or whatever for altcoins
Since this section is primarily about Bitcoin, people will give you suggestions for.. you know, bitcoin...
In theory the wallet can use any internal rules. And coinomi is also not open source.
After searching a lot, I found one tool that could be of help. It's coinomi's clone of IanColeman BIP39 tool and it puts the correct derivation paths for some of the coins. I don't know if it's all.
https://coinomi.github.io/tools/bip39/