You're fitting non standard race parts to a road bike. I think you are going to have to work it out and share your info once done!

If it were me, I would take some readings off a stock coil, and compare them to the HRC coil. For example, measure the ohms between each "spade" terminal and the HT lead, noting which gives the higher reading, and then measure the resistance the same way. Redo the tests on the HRC coils, and look for a pattern. That should indicate which pin is the "signal" pin.

Remember to take a fork off the ground side to ground the body of the HRC coil.

Of course, if someone with an RS to hand can have a close look at one of their coils, and post a description or photo, that would be really handy for you. But you don't even say if you have NF or NX style coils. It's kinda hard to help someone when you don't give all the info!