I think that you should have a range. I do babywise, and so since her current schedule is every 3.30 hours, it is really anywhere from 3-4 hours. If it is just 30 minutes, I would just feed and continue on. He may wake up a little early, but might be okay too. As for the 1-2 am, are you having your husband wake a little bit before soothing? It may help him to realize that nothing is going to happen at that time and go back to sleep on his own....but that is a personal choice.
Also, are you waking him up at 4:30 to eat, or is he? For our sleep training, we had our last feeding, and then let her tell us if she needed to eat. If I knew that she could go 6-7 hours, I would try to let her go back to sleep on her own during those random middle time wake ups, but I never woke her up to eat at night, unless she slept too late in the morning. Good luck.