We are a recordkeeper and we've been discussing that for a while and have heard it mentioned - but no solutions other than we can no longer do that. Roth rules require the "contribution" to be designated at time of deferral - so, if the contributions that cause a test to be failed, theoretically, they can't be recharacterized as Roth to correct the failed test - leaving the only option of refunds. We've talked with our trades (ACLI, SPARK, ARA, etc.) and their comment letters to the IRS have raised this issue....
Many many problems with Roth catch-ups.... Even more so with Roth employer contributions....