I'm having difficulty structuring this sentence:

I want to be sure the clause "[while/though] its legacy remains" is most clearly modifying "apartheid" in this sentence, and most clearly isn't modifying "era." How would it be best to structure this sort of sentence?

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Then, let's pretend that the children who read these books grow up in an era where apartheid's influence is waning while its legacy remains.

Then, let's pretend the children who read these books come of age in an era where apartheid's influence is waning, though its legacy remains.

At this point, let's pretend the children who read those books come of age in an era where apartheid's legacy remains (although its influence is waning).

From here, let's pretend the children who read those books come of age in an era where apartheid's influence is declining--though its legacy remains.

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Thank you.