I'm also curious as to whether there's any significance to the specific adjustments to be made. They don't seem to follow a pattern, or spell anything out. I guess there needn't be, but it would make the puzzle feel more complete, I think.
Also, 30 across - is "ate" the Scottish portion? (I don't see it in Chambers) and "etas" (which seems plural) the "rank" (which seems singlular)?
Clue was "Small Scottish portion rejected - it's rank!"
Ta.