However to to back to the original thread. I dont think I would consider taxiing back in to get refueled. That would cause so many problems its not worth mentioning.
Why not ask the company? Your on the ground, taxi time taking much longer than expected. Maybe even plan a tech stop. I had it happen once. A landing 747 dumped bits and pieces on the runway, so our departure was delayed. If I've burnt my start and taxi fuel and contingency is being burned and I'm still on the ground, plan 'A' isn't working, so its back on stand for a splash, or tech stop.