This was one of those puzzles that we literally did together. At the same time. I held the iPad Mini, and Frannie looked over my shoulder and called out answers when she knew them. The puzzles often fly by when we do it that way, and today was no exception.
We enjoyed the APPENDAGE (35A: Wing, e.g. ... or a hint to answering 17-, 23-, 49-, and 56- across) theme. The best, probably, was ESTREETBANDAGE (49A: First-aid supply for Springsteen?), but SCOTLANDYARDAGE (17A: Distance at St. Andrews golf course?) was right up there.
Seemed to play a little easy (even without the double-solve it would have, I think), with the exception of some very tough short stuff. I'm guessing that the 20A: Org. of which 18 U.S. presidents have been members (BSA) is not the "Boston Society of Architects." Wait a minute... just now, as I write this, the Boy Scouts of America spring to mind. Hmm... interesting. I'll have to look it up to see which 18 were scouts. Let's see if the same sudden realization works for ANSA (64A: Vase handle) or OMB (38A: White House fiscal grp.). Nope. I had never heard of NAT (23D: Writer Hentoff), or GARN (37D: Only U.S. senator with a unit of measure named after him), and didn't remember TEK (31D: William Shatner's sci-fi drug) or ENA (55A: Aunt in Bambi). I might have heard both, but the original Star Trek and Bambi are both fading memories.
I enjoyed the clue for LSD (10D: Trip inits.), and the one for TOES (13D: Low digits).
It was a decent enough theme, and I liked seeing things like NAMATH, OBERLIN, MACBETH and STAGGER, but there's kind of a lot of weird stuff. Meh. I guess it's fine.
Yeah, it didn't take too long with a single-solve. Knowing a bit about government, I knew OMB (Office of Management and Budget): often gives the President advice on budget matters. I also knew 30A Arcturus, e.g. (KSTAR) right away. It's a Main Sequence red giant many times larger than the Sun. I didn't remember Bambi's aunt, but since it could be only EVA or ENA, and JEAVARP didn't sound like a name, I went with the latter. I knew about the BSA-President link. I remember ads on TV in the 70s where President Ford appeared mentioning that he was an Eagle Scout. Horace must have known about 27A Statue in the Parthenon (ATHENA), and I always enjoy any mention of JED (a.k.a. Barnaby Jones). I thought that CLASSIFIEDADAGE was a somewhat loose fit with "proverb," but I guess it's not a capitalized Proverb, so it's OK. Also, for 54A Summer camp sight I originally filled CAbin, which led to troubles with crosses that were quickly resolved. I starred both 10D Trip inits. (LSD) and 53A Morsel (ORT), which I'd never heard of. I love a puzzle that I can finish, so this was a good one for me.