IMO, its still a piggyback because Hondata KPRO requires use of a TPS signal and a MAP/MAF sensor. You cannot buy KPRO and run it without your ecu, it still uses a FACTORY ECU.

EMS on the other hand, is allowed to run by itself WITHOUT a HONDA ECU. you can do individual cylinder tuning, Run map based or tps bases tuning , run carburated if you wanted to, because EMS will understand what you tell it to.

KPRO only understands within the factory honda ecu parameters