Sole proprietor designates a non spouse beneficiary of a db plan and spouse consents. That refers to the death benefit.

Can spouse also waive rights to the retirement plan benefits in advance? Or does that waiver have to be done within 60 days (or some similar timeframe) of either retirement or plan termination?

Spouse can always waive benefit to allow for the selection of another beneficiary. For plans subject to QJSA, there is a re-election period sometime between 32-35 (shooting from the hip); but the rules are designed to ALWAYS allow the spouse to allow the designation of another beneficiary.

I think the question was about receiving lifetime benefits and the answer is yes, the spouse must waive rights to the benefits at the time of distribution (within 180 days).

I'm trying to distinguish between death benefits and retirement benefits.

At retirement or plan termination the participant chooses from amongst the various forms of benefit and if he is married and chooses a lump sum or anything other than the QJSA, the spouse must consent. But i believe that must happen at the time of either retirement or the termination of the plan.

Can spouse waive any right to any future benefit now, i.e. in advance.

Bird, yes that is my question. Your post came while I was typing.

A 401k or profit sharing plan, on the other hand, if the only benfit is a lump sum, does not need spousal consent at retirement, correct?

Not by law, but the plan document could require it (although with only 1 available payment option there'd be no consent requirement). One big exception: if the PSP has old money in it from a money purchase pension plan which was transferred into the PSP en masse or if the MPPP was amended into a PSP, then the QJSA & QPSA rules apply to the old MPPP money.