Lama Ole’s answer:
I would try to do both. Help out when there is a lot to do in the center; otherwise, do your own practice. The best would be to do your practice in the center as often as possible. That way you stay in touch with the friends there and can learn from them. And it also attracts new people if someone from the center is always there, whether he just sits in the kitchen drinking coffee and greeting people, or gives a good example by practicing in the gompa.