"This will take a lot of time"

You need a client signature on the 8879 so how were you planning on getting that signature more quickly than letting the client see a copy of the return?  As a side note, we provide copies of returns so the client can review it before e-filing to increase the odds that nothing was missed on the return.  In reality, the only "review" most clients perform is to look to see how big their refund is or how much they owe.