Remake of ER filmed down under leaves a lot to be desired (7,4)

I believe the answer is:

charmed life

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'down under leaves a lot to be desired' is the definition.
I know nothing about this answer so I can't tell whether it can be defined by this definition.

'remake of er filmed' is the wordplay.
'remake' becomes 'cha' (I can't explain this - if you can you should give a lot more credence to this answer).
'of' indicates anagramming the letters (the answer comes from or 'of' the letters).
'er'+'filmed'='erfilmed'
'erfilmed' is an anagram of 'rmedlife'.
'cha'+'rmedlife'='CHARMED LIFE'

Can you help me to learn more?

I've seen this clue in The Independent.

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