43 (two words) created 1A (four words) and 3 10 14 (seven words). The latter inspired 17 30, whose work introduced the egregious 18. Elsewhere, ignore one accent.

Across

9 The first three letters of ‘skunk’ (4)

11 Duke ordering wild heroics (9, hyphened)

12 Beat wife and cover up (4)

15 Mark has no time for heart drug (5)

16 Satan, not dead, is this (4)

20 Something greasy my big cat’s brought back (7, two words)

21 One entitled to insist on touring boundaries of estate (7)

24 Engineers extra base for one railing (7)

25 Pity quiet soul (5)

26 One boring gold plate returned (5)

27 Element of...