Happy New Years Heidi...I have followed your various threads and know how immaculate your tank is. There are many foods both live, raw meat and commercially prepared that Discus will take but others don't. This can be frustrating to us hobbyist. I feed my wilds and domestics white worm that I culture in my garage. Al's cubed FDBW which seem to be a favorite and clean. I am just waiting on a new food to try called Bug Bits made by Hagan which I think is labelled now under Fluval. I too have narrowed away from any mixes for adults but do use B/H is raising fry.
Sorry that is all I have to offer but others may chime in with suggestions you may want to try.
...Ralph