I'd actually be happy if eventing was out from under the IOC's interests, so I hope for that.
Wish I could offer some insight on EKG's and horses, DW. We sometimes have a similar problem with PIT (microchip) tagging some types of animals -- if the animal has a larger body mass or the tag migrates, we might not pick it up with the reader. Is it possible for the rider to have say, an armband receiver that collects data from the transmitter so it can then be "dumped" at the end so you wouldn't have to have a zillion computers along the way? Not a live feed unless, OH OH, you then get the rider's device to tap into the cell towers and stream the data for you! Why, you're welcome! ROFL.