Different strokes... I distinguish between excess, mixed up client information that is disorganized and voluminous from clearly marked orderly highlighted or red marked pages stating (I have a stamp) DO NOT PROCESS ATTACHMENT TO FORM 1040X ONLY or 940. If the amended form is on the top, the auditor, agent, even the client is free to pay attention only to that and disregard and/or discard any and all other documentation deemed superfluous or irrelevant.
Different strokes - I have yet to be reprimanded, chastised or otherwise corrected for doing this. On the other hand, I have had relatively few amended returns of any kind.