The solution is all laid out neatly in your post.
"The daisy-chain for "Bryan < Caffe Latte < (+20 cents) Henry" does not intersect the relationship of "Austin < (+20cents) Fredrick". I've marked that neither Henry nor Bryan can have Caffe Latte, but that's the extent of the exclusions in these relationships."
caffe latte is 20 cents less than Henry.
Austin is 20 cents less than Fredrick.
Fredrick and Henry are in the same category, they're on the same side of the inequality, and the two inequalities are fixed distance of the same size (20 cents).
Henry cannot be in the same row as Fredrick, so neither can caffe latte and Austin (be in the same row).
cafe latte cannot be Austin.
You did all the work. I just read your summary. Now I'll actually go look at the puzzle to find out what I might have missed with this hasty reply