so I went ahead and moved the position of the strap button from the back of the guitar to the tip of the horn. I used the same screw and button. I drilled a very fine guide hole at a slight angle into the wider part of the horn as I wanted the button right on the tip but was scared of being too close to the edge. I then kept increasing the bit size and then when the hole was a bit smaller than the screw I fitted the button and screwed it in. It is really tight and no sign of any movement. G400 Pro now sits in a much nicer position and no more neck diving. Will keep a close eye on it over the next few days and post up a pic when I get a minute.