OPT documents sent May 13.
Receipt for OPT application from Nebraska on May-17.
I got it approved on June 9. Got an email from NCSC on June 10 that my OPT has been approved on June 9th.
June-14th USCIS case status changed that they have approved my I-765.
I have mailed my offer letter along with the application and then after two weeks emailed them that my employer is asking me to join asap. The email address is ncscfollowup.nsc at dhs dot gov . They replied me back after 5 days on June 9th that my OPT has been approved.
From the International Center they have emailed to Nebraska to expedite the process. I think it worked.
If you have a job offer, it is not difficult to expedite the OPT. It doesn't take 90 days in all cases.