Mooncricket, before you go into all the trouble of installing an Independent Coasting mechanism, you ought to try riding a regular tandem for a while. Many teams (including ours) have the differences in ability which you describe, and manage fine without it. It is a matter of compromise on the cadence, and communication. You will need compromise and communication in any case, so why not apply it to the crank? The actual power delivered to the pedals is always independent.

Independent coasting looses a communication link which is the sych chain, you might be surprised how much is carried between the riders by this simple chain, once you have settled into your team habbits. I hardly call the bumps for example, my stoker knows that if I stop pedaling and I raise my butt, a bump is likely coming, a form of dancing. Independent Coasting also adds weight and complexity to the bike. Though there are riders who swear by it is a small minority of the tandem population, it might look like a good idea, but why not find out first if its a good idea for your team?.