Sums it up pretty much in principle. The vibration will be transmitted outwards from where the pump is located. If not attenuated, it might be nuisance at best or the pump night be prone to "walking" or be transmitted along the piping. For that where piping is known to hit the other part of the roof support, place a small piece of anti vibration mat (cut to size) in between to shield it from this tendency.
Note: everyone upstairs might still hear the pump's soft humming when it's operating. That can't be avoided but if your plumber has done something marvellous that reduced the humming such that the only time you're aware that it's operating is when you're directly under it, do share. I want to know how also.