Profitable scheme developed my Mark One device, ultimately (10)

I believe the answer is:

moneymaker

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'profitable scheme' is the definition.
The answer and definition can be both related to thinking as well as being singular nouns.
Perhaps there's a link between them I don't understand?

'developed my mark one device ultimately' is the wordplay.
'developed' indicates anagramming the letters.
'ultimately' says to take the final letters.
The last letter of 'device' is 'e'.
'my'+'mark'+'one'+'e'='mymarkonee'
'mymarkonee' with letters rearranged gives 'MONEYMAKER'.

Can you help me to learn more?

(Other definitions for moneymaker that I've seen before include "Profitable undertaking" , "potential goldmine" .)

I've seen this clue in The Times.

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