YES, someone is doing it, usually the restoration shop. BUT, When it comes to replacing a BCM, you will need to program it. And unfortunately, it may cost a lot in the dealership. But can you do this on your own? For some vehicles, it's possible and it won't require a lot of equipment and expertise. While for some other cars, programming the BCM is only possible in the dealership. That is just the way it is with newer technologies. The car makers don't want to give up their proprietary systems/programs. It is for that reason that you normally replace the entire wiring system from the donor car. Use the donor's engine control module (ECM), powertrain control module (PCM), transmission control module (TCM), brake control module (BCM or EBCM), central control module (CCM), central timing module (CTM), general electronic module (GEM), body control module (BCM), and suspension control module (SCM). Then you bypass or remove the unwanted/no longer need extras (like heated seats, etc.). You will often have to bogie the sensors if they are not going to be used. The real problem is the input/output circuits. These circuits are used to either read data or send data to various components. The input circuits receive the sensors’ data and transform the signals into binary code so the processor can read it. Output circuits are used to send a signal back to adjust the position or operation of different actuators. If an input circuit used to process the O2 sensors signals were to stop working, the PCM might start injecting too much or not enough fuel to the engine. Since it can’t understand the data coming from the O2 sensors anymore, the PCM has no idea if the engine is running rich or lean and won’t keep the air/fuel ratio steady. If an output circuit is faulty, the PCM might stop sending a signal to open an injector. Or the PCM might not close the fuel pump circuit, and no fuel will reach the injectors at all.
All of this communication can cause a huge problem if not being sent and received correctly, thus replacing the entire wiring system is the way to go. Again, some sensors can be bogied, if your vehicle has o2 sensors after the cat(s) then yes a resistor can be soldered inline to make the computer think it's working and keep the check engine light from staying illuminated. Finding the wiring/sensor you need to eliminate is a bitch, but you can do it. I have done it, but to be honest, it was not worth the time/trouble. There is no plug and play adapter that I know of. Too many different makes and models and too little demand.
Best advice I can give. Use the entire donor wiring harness and install all those sensors (engine oil level, engine oil pressure, coolant temp sensor, Mass air flow sensor, intake air temp sensor, O2 sensors, knock sensors, crankshaft/camshaft position sensor, throttle position sensor, manifold absolute pressure sensor, fuel pressure sensor, coolant level sensor, Nox Sensor, exhaust temp sensor, and boost sensor (if applicable), and probably another dozen or so I have missed, into your restomod. It is not easy, which is why the cost to do it is so high.
Again, best of luck with your build!