I enjoyed this though I found it very challenging, hence the late post (although I suspect on a holiday weekend this conversation will continue). I wonder if Paul had thoughts left over from his recent theme that led him into this one?
Like others, I went down the wrong trail with 3d and 17a for ages but eventually 27 straightened me out. I’m surprised nobody’s pointed out the links to 11a’s work in the clue for 11a and at the start of 14a, nor the appearance of the false 3d in the middle of 19a - not sure these are accidental, given Paul’s liking for links all over the place!
As for the homophones, they usually raise a smile and these ones are less vulnerable to regional differences in pronunciations than we often see. Concerning25d, I’m sure we all know the difference between a buffalo and a bison?