Issues with crank sensor and ECM?

Dear friends of the 2CarPros,

I have the car listed above Sedan, 4 doors, Limited Edition.
For a couple of times in the last four weeks (once a week), my car didn't turn on as it should. It took like 2 seconds longer and the RPM gauge didn't move from its stationary position. Pushing the accelerator pedal all way down would increase the RPM just a little, but the RPM gauge would still stay in its stationary position. No warning lights like the engine light turned on.
When it happened for the first time, I was still able to drive the car, although with low power. After the second time, I figured out that turning the car immediately off and waiting for 5 – 10 minutes before turning it on again would “fix” the problem.
However, a couple of days ago, the car lost power while driving on a highway. At this time, the engine warning light turned on. The engine ran normally again after 3 hours (when it cooled down). I continued driving but the car lost power again after only a few miles.
The car was polled to a Hyundai dealership. They scanned the car and found two DTCS. In their words: “One is for the crank sensor, which can cause all of your symptoms, and one is for the ECM which can cause slow crank, loss of power as well”.
As far as I understood, the crank sensor may be responsible for all this set of problems and symptoms. In addition, replacing the ECM is expensive and the dealership needs 45 days to receive this part to be able to fix my car. So, I am wondering if we should replace the crank sensor first and see if this would solve the issue. Even if not completely, it could at least allow me to use the car in the city (for short distances), while waiting for the ECM part.
All these said, I would appreciate it if someone could give me his/her opinion about the following questions:
1. Do you think replacing only the crank sensor may solve the issue? Should I try it?
2. Does the replacement of only the crank sensor require any kind of reprogramming? If not, I guess I can replace it by myself.
3. Regarding the ECM, what about sending my ECM for repair or buying a used one? There are many companies that provide this service. Any suggestions for a company?
Thanks in advance!
Sincerely,

Giovani