I'm pretty sure you could put a single coil in the Griffin the same way you can on the Velocity or any other dual-post, dual-airflow RBA. There is no single-coil airflow option on the Griffin either so it might be a bit airy or not as flavorful as in an RBA that has a dedicated single-coil airflow configuration... but it is *possible*.
To be clear, I am referring to a single coil set-up as in the video I posted, being centered in the deck, not one coil on one side. This at least evens out the airflow when there is no single coil option.
Like I said, I believe it is POSSIBLE but the way the wick channels are set up and the way the airflow works, I don't believe it would be at all satisfying in this particular tank and probably difficult to wick. Normally I am someone who prefers single coils... but a single, centered coil isn't amazing on the Velocity. It's fine though. IME toppers that are
meant for dual coils usually work better with dual coils

But it depends.
I have not seen that video from Grimm. I will check it out.