Wow, their eating habits are so similar!
ds will only eat McDonald chips and potato waffles have to have salt on them or he wont eat them. His food texture has to be crunchy or solid, he has a fear of mashed potato! The taste has to be either salty or sweet (OT told me sweet is the most tolerable taste, followed by salty)
Ds is verbal (limited conversation skills) but i think its hard to address even psychologically, as he doesnt know why he feels the way he does if you see what i mean. All he ever says is 'its disgusting' or 'yuk' if shown a food not on his 'ok' list.
Over the years ive tried, you are not leaving the table, not making his usual food available, taking him shopping and letting him choose, timers, making it into a game, faces, patterns, letting him help me cook, rewards, bribery, putting a little bit of a new food on his plate or on the table or anywhere near him, making menus, visual sequence charts, making small changes etc, etc.
No success, he did once eat a chicken nuggett a few years ago! He also has problems with drinking.
Im all out of ideas, i have to constantly prompt him to eat or drink even the food that is on his 'ok' list, if i didnt he just wouldnt eat or drink at all. Hopefully CAMHS or the feeding clinic will offer some ideas to try.
Im just grateful that he is eating/drinking anything at all, im a parent who is happy that ds is eating sweets!
Sounds like your ds is making great progress, chocolate and jelly!