Four down.
Definition is the final word, which is a misprint.
Four letter word for groom; plus what words 3, 4, 5 say.
Are the first four extra words found in 16, 20, 27, 35 down ?
Otherwise about to admit defeat !
DFG2, 4 D was tackled, sorted earlier.
No, the first four extra words aren't found in what you've listed - but I'm not sure if that's what you meant to ask... if the answer was yes, where are the rest of the extra words going to be found, there's no clues left!
Ashers - I can smile too after four days !
Thanks Malone for your reassurance.
Went wrong on the two twenties.
The “locations” in the twelve extra words hindered, you did not know what to do with them until the very end.
Had to search for number 37 high light.
I'm hoping that if someone could help me with 1A I just might manage to finish the last 10% of the grid. No idea about any of the rest of it!
Mossy plant sadly struggling next to pier's cap (12)
Sybila, for 1a the definition is the first two words. Anagram (“struggling”) of sadly followed by the cap of a pier - a surprising definition of a word more commonly associated with soft furnishings.
DFG2, glad you made it all the way through! Yes, I mentioned earlier that the locations bit wasn't involved until the end- just a litttle added difficulty, I suppose!