Seat cushions for Avalon front seats.

I like to sit high in the saddle and often use seat cushions to get the seat height I like. Not short at 5’ 10” but I like height.
But the cushion places my back 1 to 1.5” higher than the seat designers thought it would be.
A few days ago my back was aching and just reached down and pulled the fat cushion out. The relief was almost instant. Had to adjust everything and much of it was easy with all the seat and mirror adjustment features. After two days sitting on the seat where my back was intended to be all is well.
However the cushion is far softer than the seat bottom but no sore butt so far.

I know the best way to accomplish what I want is to raise the seat. That would be easy if the mounting screws/bolts were vertical but I haven’t looked closely enough to tell if it will be easy. I think the front bolts are at an angle.