Really great puzzle, quite a challenge and so satisfying when it finally came together. I got slowed down by the NW corner where ASTO for 17A, OMNOM for 20A, and GROOVE for 4D all fit together so nicely! And of course there were so many terrific clues - I gotta shout out the cleverness of the POPEYE and GAMER clues and the sheer audacity of COFFIN!
Exactly my experience. I didn’t know DUVALL and Little Little Debbie, and I couldn’t even see DONUT because I had RAN AN EXPERIMENT, which works if “put” is past tense.