BTG has no replay protection either. I would treat your first interaction with BTG as risky, when you import your BTC wallet you're taking a risk with the software you're using, when you make a transaction you're taking a risk that it could be "replayed" on the other blockchain.

The advice I have seen, that I would trust, is to move all your BTC to a new wallet before you touch BTG - that way if something goes wrong the more valuable BTC are already elsewhere in a wallet that will never have anything to do with BTG.