The recipe says cook the pineapple in water and lemon juice until tender before adding to cooked apple.  Would waiting until 'apple jam' (ie, cooked apple with sugar added and boiled up) is nearly at setting point - then adding pineapple at last minute - get over the too sweet/burning problems, do you think?  I'm considering, contemplating, and generally procrastinating over this one.  Meanwhile the pineapple is getting past its best.  Ho hum - another day, another pineapple!