I can only begin to have a glimmer of an understanding for how difficult this puzzle must have been to create. There's this CHESS BOARD in the middle of the grid, first off. Note how all the crossword black squares fall on black squares of the chess board. Then, there's a chess position created on the board, with crossword letters standing in for chess pieces - R for rook, B for bishop, P for pawn, K for king, and N for knight. The chess position is not only a legal and reasonable endgame, it is actually set up for CHECKMATEINONE, and that by moving KNIGHTTOBEIGHT (knight to B-8). This does in fact create a checkmate, as the black King on D7 in placed in check by the knight, and can't move away due to the rook on G8, the rook on E1, and the bishop on B4 blocking all its moves.
Holy chess pieces, Batman!
I bet Mr. Reuter is glad he came up with a chess position with no queens (Qs) in place...
As impressed as I am, I suspect that solvers with little or no chess experience might not find the puzzle exciting. The grid is essentially nine (9!) minipuzzles, due to the extreme hypersegmentation I'm sure was essential in creating the middle section. We get not just EZINE but ENOTE (and ESTOPS? - Okay, that's not actually an internet age coinage, but rather a medieval legal term). I lost track of the number of compound answers: things like CHOPUP, MAKESIT, LANDEDON. Although OOZESOUT is perfect for molasses.
Answers I ADORE include PROMINENT ("No, I'm not prominent..."), NOSFERATU, and GOSSAMER. I fell into the trap of 66A: Eve's counterpart (MORN) by entering "Adam." And who knew that SPOKANE hosted the 1974 World's Fair? Who knew that the World's Fair is still going on, and that the most recent was in 2017 in Astana, Kazakhstan?
Finally, it's crazy seeing AUNTIEEM in the puzzle, just for that IEE letter combo.
So I enjoyed the puzzle, but I can see that it might be a mixed bag for some.