I recently reviewed a large plan that had regular recordkeeping fee benchmarking by their current advisor.
The Benchmark reports showed that their current recordkeeper pricing was well under midpoint for historical pricing against similar sized plans in their same industry. The sponsor was pleased to be in this position.
I explained my concerns about "benchmarking" recordkeeping reports as looking historically vs. current pricing recordkeeping comparison reports which look forward. The sponsor was skeptical at first and had their aha moment when I showed 3 other quality recordkeepers who would perform a similar level of service at half the price of their current recordkeeper.
My favorite quote from the following article is: "The law doesn’t require RFPs; instead, it requires that fiduciaries spend no more than reasonable amounts for services and investments".
https://401kspecialistmag.com/fred-reish-retirement-plan-litigation-lessons/