I have just made one of my favourite pies (coconut cream) and it was delicious, but it didn't pack a ton of coconut flavour as I was striving for. I made a shortbread crust with coconut that I toasted, nice and brown. The filling contained coconut, a full can of full fat coconut milk, and pure coconut extract. (Added after the cooking so it didn't lose its flavour). I topped it with 35% whipped cream which I also added pure coconut extract. The top was sprinkled with more toasted coconut. What more could I have done to really emphasize the coconut flavour? I know coconut is a mild flavour, but I thought that with all the different layers of coconut flavour I added, it would be much more pronounced.
Maybe your tastebuds are getting saturated by all that coconut, and your receptors failing to register the coconut sensation since they have become acclimated. I wonder if it is time to work on contrast. I.e. make the filling very coconutty (and it seems you are doing that already), but keep the crust & whipped cream topping "plain" (i.e. don't bother coconutizing them at all). Would the extra coconutty filling then stand out more in contrast to the "background" parts of the pie? The crust and topping might give your sensory receptors a chance to re-calibrate in between bursts of coconut overload.
Just an idle thought, but I can't see how there is room for any more coconut intensity than you have already put into this pie. Your answer to Spagirl's question also supports the idea that you may have reached coconut maximum. [as to whether you have ever had a sufficiently intense coconut pie?..."Not really."]