You can physically swap ECUs but you will still need a new 2016 auto rom tune. So i do not see the point in swapping ecu it is a tedious process outlined here
http://www.ft86club.com/forums/showthread.php?t=102810
But again you will lose your tune, because you will need a entirely different rom a tuner will need to setup as if its a brand new tune file.
I am not 100% what will happen to the ecutek license it may be possible to keep it in this scenario. But idk if it is worth the headache and potential issues over a 300$ license. Note you will need tactrix cable which is about 180$, so if your lucky you save 120$.