I'd be checking to ensure there are no differences in the harnesses between the 14 and 15, especially since they have different powertrains. I'd also check to see if there is a difference in the main AC compressor and/or condenser if the vehicle has AUX AC. There could be changes to the orifice tubes, fan control, etc. as well. It will also change the weight of the charge to put into the system after the drier is replaced and it's pulled down, so if you need the specs from a 15 Ecoboost with rear AC, I can send you a picture of the sticker on my PIU. I'd replace all O-rings and seals within the system and leave it under vacuum for a good bit of time to ensure you don't have any leaks. As others mentioned, you'll have BCM and possibly needing to replace/reprogram the HVAC controller.
What I'd do first is to lay in the base non-refrigerant components of the system and see if I can get the vehicle to recognize and control those components. If so, I'd proceed with the refrigerant side of the system. It would suck to go through all of that work and dressing in all of the piping/parts/harnesses, only to find out you cannot enable proper control or enablement of the system. Do as much of that as you can on a bench or with the parts loosely arranged in the vehicle. Since you can always revert the programming using the AS-Built data, the risk to undoing the programming changes is minimal.