but Electrum is an open source project, and anyone who can and wants can simply fork it and create an alternative for an altcoin.
and they have done it for Litecoin but never for Ethereum.
original for bitcoin: https://github.com/spesmilo/electrum
fork for Litecoin: https://github.com/pooler/electrum-ltc
If i only need one instance of Electrum, I presume I'll have to establish a wallet for each coin.
and they will have different wallet files which you have to backup separately (back up Seed or wallet file).
the version for bitcoin cash is a little different. the only difference is that it copies all your bitcoin wallets to its own repository and creates the new wallet for bitcoin cash based on them.
https://github.com/fyookball/electrum