As I completed the grid, I found the anagramization of T,A,L,E,S at the end of each theme answer quickly GOINGSTALE. It was a nice that the theme's big finish was LASTBUTNOTLEAST, but the presence of NICOLATESLA not withstanding, I felt the puzzle lacked electricity.
I did enjoy KEPI and MELEE, which are both fun words. And 39A. Prevents litter? (SPAYS) was clever, but the parade of LII, LIE, LET, LPS, SSR, ASSN, AKA, BAA, AHS, HTS, CTS, STR, SKA and TASK, to name a few, elicited more than a few muttered TSKS as I puzzed.
Maybe this is too many CARPS, but I am not a fan of LASE (Cut with a beam) as a verb, or NULLS for that matter (48D. Makes void). I thought of a few possible sentences using nulls as the main verb, but it would upset Horace if I printed them here, so you'll have to contact me off blog if you're interested. :)
The clue for 1A. won't win any MEDALS (Things that may be displayed on a general's chest), but as an entry in and of itself, it's not bad.
On TOTHE next.