Had 3 S corp extensions rejected due to IRS not processing 2553's timely.  Had to mail those in with a note attached.  A few states had to mail in to.  

I stop accepting new returns as of last Sunday in March, otherwise everyone would wait until last minute.  I get so many drop-offs and Client Portal uploads scheduling is out of my control.

I probably have turned down over 200 potential clients.  No time, no staff, no toner or staples.  My two tax season favorite songs:  I Don't Care Anymore and Running on Empty.