Yes, that makes sense that you can control required timing based on how you build the coil, but changing the time sounds a bit easier to reused the same coil on multiple calibers, but I see there are some good threads on this on SnipersHide and Accurate Shooter, so I'll read up some more. In the video he's using 3.75 seconds.

I am thinking you could get something like a 2' or even longer 1"x2" strip and drill out holes so you can have a long, linear shell holder and just move right on down the line pretty quickly.