Yes. It is more formal. There have previous discussions of Americans (mostly) using the second conditional with past subjunctive and British (mostly) using the second conditional with the simple past, but switching to the subjunctive for formal situations.
Here is a related discussion:
And here is a multi-topic discussion about American and British English:
Present subjunctive (for possibility / indirect command, etc.) (“American” usage is considered more standard, so British speakers may follow it more in formal situations):
US: It’s important that he study tomorrow. (=it’s important for him to study tomorrow.)
UK: It’s important that he studies tomorrow.
Past subjunctive (unreal present conditional):
US: If that were true, it would be enough.
UK: If that was true, it would be enough.