"Amended" Prototype: When to file for a determination letter?

[Scott]

A company that would fall into Cycle A adopted a Fidelity prototype 401(k) plan several years ago. In 2003, it amended the plan to provide for multiple matching contribution formulas, which took it out of prototype status ("amended prototype"). Fidelity has issued a notice to its employers advising them that "the vast majority" of amended prototype plans (i.e., those that have not been amended "extensively" off prototype) can file under the 6-year prototype cycle and that it would actually do more harm than good to file an amended prototype plan during the individually-designed 5-year cycle.

However, this article by Deloitte (recently appearing on BenefitsLink) says that only amended prototype plans that were amended after February 16, 2005 can take advantage of the 6-year cycle and all others must file during the applicable 5-year cycle.

Both articles state that they are based on conversations with IRS officials.

Fidelity appears to rely on Section 19 of Rev. Proc. 2005-66. Deloitte appears to rely on Section 17.02 of Rev. Proc. 2005-66.

The company felt reasonably comfortable with Fidelity's position until it came across the Deloitte article. Obviously with the January 31 deadline fast approaching, it needs to decide who is right quickly. Any thoughts?

[Blinky the 3-eyed Fish]

Why wouldn't you just have them sign an 8905?