BIP39 specifies different word lists in different languages. But I wonder if the word list generated by a software that gives me French words (e.g. Copay on iOS) can be used to re-create the same wallet using another software that expects English words.

I looked at the section From mnemonic to seed of the BIP39 specification. Given that the mnemonic sentence itself is fed through the PBKDF2 function, rather than first looking up the indices of the words in the dictionary, I guess that the answer is no, and a French list can't be easily converted into an English list. Is this correct?

Doesn't this drastically reduce the interoperability of wallets using different word lists? Specifically, how can I ensure that the word list I have for a wallet can be used in another software than the one it was generated with?