TALES, STEAL, SLATE, STALE, TESLA, and LEAST = SIX themers in total! Often, anagram puzzles can result in bleh themers due to the ...
read moreTALES, STEAL, SLATE, STALE, TESLA, and LEAST = SIX themers in total! Often, anagram puzzles can result in bleh themers due to the difficulty of finding good anagrams, but Freddie did a great job. CANTERBURY TALES and the crazy inventor NIKOLA TESLA are my favorites (I'm also a former engineer). And LAST BUT NOT LEAST in the last theme position is a beautiful touch.

At first, I hesitated on GOING STALE, as I'm used to hearing WENT STALE or GO STALE. (I'm very careful in adding different tenses into our word list, as sometimes a particular tense hits my ear wrong.) But after some thought, GOING STALE is fine. Many food items in my kitchen are in the process of GOING STALE right now.
Not only does Freddie use six themers, but all of them are fairly long — a ton of material to build around. An incredibly rough grid-building task.
The lower left is a good example of the problems that high theme density creates. Working around the starts of NIKOLA TESLA and LAST BUT NOT LEAST means that three down answers are already heavily constrained. I think the result is decent, but for a Tuesday puzzle, I worry that IZAAK crossing UZI and SKYE might give some solvers fits. As a constructor, you want to set solvers up for a fair win. I'm not sure this does that.
Same with KEPI / SISAL in the upper right. I know what a KEPI is because it was a themer in one of my puzzles, but faced with that intersection otherwise … oof, that would be rough.
A lot of crossword glue elsewhere: A MUST and TO THE as long partials, SSR, USTA, ASSN, LII, etc. = too much for one puzzle, especially when early-week, newer solvers can be turned off.
And NULLS ... nullifies, yeah?
Neat to get so many strong phrases using the anagrammed letters — I can't remember six that were this good in any other anagramming puzzle — but a heavy price to pay in grid execution.