Hello madamearcati,
I think the puzzle as a whole is a brilliant construction and as I said @post 13 it must have take Arcadia a good while to put together.
I will leave it to quisling and others to get back to you on your request.
The only thought I had was whether, instead of synonyms scattered through the clues to grids A to D, there could have been a separate set of cryptic clues or allusions to the 8 rearranged grid E entries, under grid E. Easier said than done of course but one idea would be split each of the 8-letter words into 2x4, provide clues to each 4-letter word (or non-word) and then ask solvers to rearrange correctly in the final grid. Or something on those lines, to make the final grid a 'solvable challenge'.
Have a lovely Christmas...