Weeeeeeeeeell, it´s kinda "imposible". Well, is posisble, actually, but it would a meanless tons of works for the servers.
If you have noticed, the prizes for PF and RIFT are not given instantly after the event ends, that´s because the server has to arrange all the points in order to determinate who is tops, and who is only 10%, and so.
If we wanted anyway to have this and give tons and tons on money to HVS to make it happen, then the game would delay (They would have to close the PF to make good counts) for 1-2 hours everytime to determinate who is to10%, top 100, etc... and well, you don´t want to lose 1-2 hours x day, or even more, of those events, right??
And everything they said above x2.....