Let's stop here. How exactly are you planning to achieve that?
The main issue will be that Spark has no separate transceiver board. But if you somehow manage to overcome that - it would work, to some extent. The underlying communication protocol was extended between Ph3 and Spark, but many simple packets exchanged between RC and the drone are the same. What exactly would work, and what wouldn't - hard to say. You would definitely have to do some software modifications to make everything fully functional.