I think the seed phrase should be enough as your backup unless you have some things you want to backup like labels or gap limits then you need to back up the wallet file to restore all labels to a new wallet.
However, if there's nothing you have to back up from your Ravencoin Electrum wallet you shouldn't have any problem when restoring your wallet with seed phrase in the future all assets are inside your hardware wallet derived from your seed phrase once you restore it all ravencoin funds should be there.