Change of a blueprint struggling commercially (12)

I believe the answer is:

unprofitable

I'm a little stuck... Click here to teach me more about this clue!

'struggling commercially' is the definition.
I can't tell whether this defines the answer.

'change of a blueprint' is the wordplay.
'change' indicates anagramming the letters.
'of'+'a'+'blueprint'='ofablueprint'
'ofablueprint' is an anagram of 'UNPROFITABLE'.

Can you help me to learn more?

(Other definitions for unprofitable that I've seen before include "Not beneficial" , "Vain" .)

I've seen this clue in The Times.

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