eddie If the question is how to trigger new suggestions calculation, then any change in the person faces (assigining new one manually, for example, or accepting suggestion) will trigger recalculation.
If the question is how to make it find more faces - this on is difficult. Typically, accepting more faces or adding more manually will give program more samples to compare to, leading to more suggestions (if there is still something to offer). But it is a bit more complicated than that, unfortunately.