Glad this week was straightforward as I had to work all day and didn't start until 10PM. Am I correct that this is the only circular puzzle we've had this year?
With regard to 43, I think that this is a "double wordplay" clue, as "that is" can give SC (abbreviation for scilicet) and one of the many meanings for "in" given by Chambers is AT. The other wordplay, as already noted, is SCAT(he) for "savage (not male)", and the definition is "dropping" (or perhaps the whole clue can be the definition).
I particularly liked the clue for 9, which took a little time for the penny to drop.