I couldn't believe I had COLPORTEUR correct, but all the crosses worked. Happily, when I filled in my final square at the crossing of EGAN and ASSN, I got the happy little tune. Clearly it comes from French, where it apparently means a peddler, and then got associated with religious literature. Definitely a new word for me.
Melbourne is in Florida, apparently, not Australia. That fooled me for a while. I enjoyed all three long across answers, but should the clue have had a "familiarly" attached to it for FLORIDATECH? The full name is Florida Institute of Technology. Not that that bothered me. I wouldn't have gotten it without most of the crosses. Meanwhile, FLEXITARIAN is lovely, and PALEBLUEDOT is of course, excellent.
DONTTHATBEATALL? I'd say. I love that phrase, and it's a wonderful 15-letter crossing answer.
The rest of the puzzle has some nice high points. 10D: Be subtly and snarkily insulting (THROWSHADE) is great and contemporary. EGOSURF has been seen a number of times by now in the puzzle, so it's a little less sparkling.
DIETETICS and ANTENATAL are all right. I don't know why it took me so long to figure out the latter.
1A: Honor in a big way (FETE) - C. Nothing special to start a Saturday.
Fave: CHARY (16A: Word that's its own synonym when its first two letters are replaced with "w") - such an involved clue! It also reminds me G&S, namely Iolanthe:
A plague on this vagary
I'm in a nice quandary
Of hasty tones
With dames unknown
I ought to be more chary...
Least fave: ASSN (20A: N.E.A. member?: Abbr.). Yeah. Abbreviated answer from an abbreviation, not improved much by the slightly clever clue.
I'm not sure if the puzzle is quite TOPSHELF, but I enjoyed it over all.