I think the REOmizer and a7 have a similar relationship with the hole in the center.
Also note how on your ERA, the juice hole Dispenses juice out of both sides of the post - if you wrap the tail around the post and back under the coil you may achieve better saturation?
The coil tightness is easy to attain when you scrunch it against the end of whatever you twisted it up on. I think your coils look great.
Shot thru cyberspace with my iGun