jerry,
I applied for my 485 in Jan 2002 and completed 6 yrs of H1 in Aug 2002. EAD card receivd in March 2002. My lawyer told me I had the option to go for 1 year H1 extension or work using EAD card. I opted for the latter, to save money.
No problems at all. I re-entered US in Dec 2002 on my EAD. All went smoothly.
Unless you have any other pressing reason, extension of H1 is not required if you have a valid EAD card. You do not need to notify anybody about opting to work on EAD and not extending H1.
RD 1/17
ND 1/31