well the code from the official BSV repository here: https://github.com/bitcoin-sv/bitcoin-sv/blob/88ee5b7012e03eb99ccaf695eab0b2f0fff7cb5c/src/script/interpreter.cpp#L1813-L1894 says otherwise.
apart from using a forkid is exactly the same as how SegWit transactions are being serialized and hashed before signing.
https://github.com/bitcoin/bitcoin/blob/3e1bf71064ccb98d0684753e844c80d6da421287/src/script/interpreter.cpp#L1234-L1279