May an IRA sponsor require that all distributions to beneficiaries be paid out in a lump sum rather than over the beneficiary's life expectancy?

IRA distribution provisions usually provide that distributions will be paid in accordance with the MRD rules of IRC 401(a)(9) whcih permit payment over a beneficary's life expectancy. However there is no requirement that such option be provided. If the IRA custodian only permits payment in a lump sum the beneficiary can move the funds to another IRA custodian tax free as a trustee to trustee transfer.