Lost Participant / Address Changes?

https://www.docusign.com/products/identify

I was researching about esignatures, which for some reason I incredibly interested in??, and came across this method of identifying that an individual is who they say they are.  This sounds an awful lot like something that is very important, especially when some termiated employee comes back 10 years later for their money having moved 3 times, etc.

Anyone ever used something like this (or this for that matter)?

Some of my client plans with Empower Retirement use an identity-proofing service to facilitate online enrollment—for elective contributions—of a participant on whom the recordkeeper lacks both an email address and a telephone number.

Many recordkeepers, and some third-party administrators, use identity-control procedures (or the plan administrator’s instruction) for an address change.

Many plans restrict a distribution, and even a loan, for some interval after an address change.

Some plans require a Medallion Signature Guarantee for a distribution of, for example, $100,000 or more.

About identity-control and knowledge-based-authentication services, several suppliers, including Experian, offer services.

Here’s my question for BenefitsLink neighbors:

Imagine a plan for which the employer pays no plan-administration expense; all expenses must be borne by participants’ (and beneficiaries’) accounts.  The plan’s administrator uses identity-proofing services.  Assume those services are not embedded in a third-party administrator’s or recordkeeper’s fee.  How should the administrator allocate among individuals’ accounts the plan’s expenses for the identity-proofing services?

1.    to only those individuals on whom the administrator needed to test identity?

2.    to all individual accounts “per capita”?

3.    to all individual accounts in proportion to account balances?

4.    something else?