Life expectancy vs 5-year rule

Plan document facts:

• The only pre-retirement death benefit allowed is what is required by law (the minimum spouse's death benefit)
• It can only be paid as a life annuity to the spouse
• The plan contains language allowing "election to allow participants or beneficiaries to elect 5-year rule". This language can be found on page 132 of the IRS' Defined Benefit Plan LRM package.

The obvious issue here is that the plan does not provide for a death benefit where the entire interest can be distributed by the end of the calendar year which contains the 5th anniversary of the date of death. Is this just a situation where, for this particular qualified plan, this election is not applicable? Or am I missing something?

The 5-year rule language is the standard/generic RMD provision, but a DBP can certainly provide only the QPSA in which case the 5-year rule would not be an option.