In my last post I brought up the unusual pressure the pads exerted, thanks for noticing!
Only trying to help here, as you've probably done this, but have you tried using a pad or something under your saddle when he's going through his 'light' phases? Gel pads are usually very good.
In my defence of my saddle fitting my girl, believe me she's telling me that her saddle doesn't fit! As soon as I have a horse who isn't working quite right I go through the whole process, chiro-saddle-teeth, so your 'stab' hurt