I had a rocket where I would put the charges down near the motor. I stopped bothering because unless your recovery gear is wrapped up and tight in the BT so it acts as a piston, the ejection charge doesn't really move the recovery gear much. I know most people feel the charge pushes the gear out, but mostly it's the pressure in the BT that pushes the nosecone off and the NC is what pulls the recovery gear out. Having the electronics in the NC will add some inertia to the nose cone and help it pull the gear out. Unless you have your gear acting as a tight piston, ejection may work better with the charge just below the NC.
The other advantage of the charge under the NC, the gear will tend to push down on top of the motor during acceleration during motor burn. The NC charge will be further from the gear and have less chance of burning/melting nylon.
Just some points to consider... Good luck.
