Started slowly , ground to a halt, got slowly going again, gave up. Couldn't get 4 and 24a nor 6,9 and and 20d.
Did not know the answer to 4a meant over hasty.
For 9d I had never heard of either which makes that clue hard.
Still don't get 18a (though I guessed it) -how does putting a full stop after Berengar help please? And sorry the other hint isn't helping me either.