some clients filed there own paper extension. should I attach a PDF to federal and state returns when I efile

[IRonMaN]

Nope, it means nothing to the IRS.  They want to see the one that was sent in timely.  Attaching an extension that was maybe timely filed or never filed or filed 2 weeks after the due date does nothing.

[BobKamman]

My concern would be whether the paper 4868 gets processed before the electronic return.  If a late-filing penalty is assessed, you'll find out.