Heft of punishments accepted by workers, possibly? (9)

I believe the answer is:

beefiness

'heft' is the definition.
(thesaurus)

'punishments accepted by workers possibly?' is the wordplay.
'punishments' becomes 'fines' (fine is a kind of punishment).
'accepted by' indicates putting letters inside (inserted letters are accepted).
'workers possibly?' becomes 'bees' (worker bees).
'fines' placed into 'bees' is 'BEEFINESS'.

'of' is the link.

(Another definition for beefiness that I've seen is " Muscular appearance".)

I've seen this clue in The Times.

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