I know you only asked about the psyllium, but I just have to open my big mouth about other stuff too! LOL Here goes:
re the pineapple: Use fresh instead. I think they're in season now anyway.
And that sounds like a LOT of lemon, and a lot of sweetener to "counter" all the lemon and WOW, 3/4 c seems like a ton of psyllium to me too!
My ideas are to use a little ground flax maybe , or whole chia seeds to "sop up" some of the excess liquid. (I just don't like ground chia seeds --brings out a bitter flavor, IMO) as well as some extra dried organic coconut.
Re the coconut, you must use organic or they can use some bad stuff in drying. And even if it is organic, it's probably heated to about 175---
And now, mind you, I've not tried this recipe, so I'm only guessing! But here's another idea: I think it's Cafe Gratitude who makes a similar raw pie from pineapple, dried coconut, and apricots on a cashew nut crust. I don't believe they use any flax or psyllium - the coconut and dried apricots sop up the liquid. You could try winging it, by dicing your pineapple, and putting a little in a blender, then soaking some cut up apricots in that blended pineapple juice for a couple hours. Then combining all with handfuls of coconut, a squeeze of lemon and then sweeten to taste. A pinch of salt and the seeds from a vanilla bean would add some good flavor/bring out the sweetness.
Then pour over your crust, sprinkle on a little coconut.
My thoughts anyway!