fisrt, thank you for your answer. : )
second, it is a reading passage. and the answer of what scholars hold is that they believe that a vigorous and healthy architecture would not usually employ false surfaces or imitation building materials.
however, as you put it, the scholars hold that these practices should not be limited in only in the later phases and should be confined at that time. And I think what the answer mean is that scholars also think it should be limited from the word "would".
by the way, what does the word "as" mean? does it mean " equally" or "even though"? at first glance, I think it means equally. and you inversly interpret it into " even though". How can I distinguish what "as" mean under certain circumstance?
thank you