I've waited four days and had no reply.  I called Lacerte support and after an hour I got confirmation that what I suspected is true: The Modify/Delete buttons are grayed out because I haven't submitted my EFIN info.  Since posting this on Tuesday, 2/16/21, my application for EFIN has been approved and I'm waiting on a letter from the IRS.  I'll see if submission of this info to Lacerte will change the accessibility for editing preparers.

Thanks anyway.

Joe Hart