Ejaculation and the consequent refractory period are physiologically / neurologically connected. Once ejaculation occurs, the male erection will subside,
In some men, the penis may remain tumescent, but not truly erect, such that they might continue to be useful in the context of penetration. This is pretty rare, usually with men who are trained to service a woman. With most men, once they cum, "ruined orgasm" or otherwise, they will go through the refractory cycle.
The most effective strategy is to train the male to delay and control ejaculation. Not all are trainable.