Plan qualification question

[fiona1]

Plan Sponsor is in Cycle C - as they have an individually designed plan. They filed Form 5300 by the 1/31/2009 deadline. They have not received a Determination Letter yet.

They just recently amended their plan for some minor revisions.

According to Rev. Proc. 2010-6, if they haven't rec'd a DL yet, they "must" send the discretionary amendment to the IRS and it may be included as part of the determination. Here is the wording:

In addition, the applicant must send the Service any amendments that are adopted and/or proposed after the date of the determination letter application and before the Service issues the determination letter. The applicant must submit a cover letter that references the date that the pending application was submitted, the identity of the employer and the plan, and any other helpful identifying information. The amendments must be attached to the letter. Send the cover letter and the attachments to: Internal Revenue Service, TE/GE Correspondence Unit, P.O. Box 2508, Room 4024, Cincinnati, Ohio 45201. Although all such amendments must be provided to the Service, it is possible that the determination letter may not provide reliance for all of these amendments. See, Rev. Proc. 2007-44 for the scope of the Service’s review with respect to a particular determination letter application.

Has anyone had experience with this? Is it common for a plan sponsor to send amendments to the IRS in this manner? Are there any repercussions of not sending the amendment - since it says the applicant "must" send them to the Service? I would have assumed the plan sponsor would just wait until their next cycle is due to include any new discretionary amendments.