It *is* doable... it just isn't a straightforward "point and click" exercise... you need to find all the UTXOs contained in each 2FA address and manually create and sign a transaction to move these UTXOs to the BTG wallet address of your choice (personal wallet or exchange etc). This means typing in a bunch of commands on the Electrum and BitcoinGold Core wallet consoles.

It also means that you need to have the BitcoinGold "Core" wallet downloaded, installed and fully synced.