I do agree it would have been easier to just stick to xpubs and then specify derivation path/script type/etc separately in order to generate the correct type of addresses, which is exactly what Core is doing with descriptors. It would avoid scenarios like this one where you have to convert Zprvs from Electrum to xprvs in order to import them in to Core.

As specified in BIP86, Taproot should use xprvs/xpubs, but there is nothing stopping software using zprvs/zpubs for Taproot. Although given that Taproot addresses can be key path or script path, then the whole Z/z separation for script hash/pubkey hash falls apart.