Payroll advance

The Plan defines W-2 compensation to exclude reimbursements and fringe benefits, which is fairly straightforward. However, do some plans treat a taxable pay advance issued under a signed agreement and repaid over multiple payrolls, as eligible Plan compensation?

While it technically aligns with the definition of eligible compensation, complications may arise if an employee reduces their contribution election after deferring into the Plan using the advance. Additionally, if a team member leaves early, the company may initiate a clawback, withholding the remaining balance from their final paycheck but possibly no reduction of 401(k) contributions. Does that mean we have to remove the previous 401(k) contribution from the Plan? 

It sounds to me the easiest way to move forward is this pay advance not be considered eligible compensation due to the downstream impacts and operational headache of the clawback or advance payment. 

Thanks.