I followed current thinking for best practice, for mounting the inductors, in terms of spacing and orientation and had the boards in the standard location behind the big bass driver magnet, mounted below behind the ABR and also mounted external.
To be honest, I couldn't hear any significant difference in any of it, I certainly couldn't make up my mind if any one thing sounded better, or if reorienting the coils had made a difference. Other changes had made a far greater impact, so these days I just recommend the simple cap renewal on the stock boards. This gave 95% of the improvement I gained, all the extra work (the main chunk of the total) I did, made little if any difference, you are getting down to very very small changes to the sound, where you can fool yourself as to what if anything has changed and also if it is any better. In this particular set up, I think coil placement would be as much about peace of mind as any tangible benefit, so I will leave that one up to you.