A developer in the district may request that the Planning Board and/or Township waive or modify cost-generating requirements in the zoning, subdivision or site plan regulations except for density limitations, waive or reduce fees, or grant tax abatement to the extent authorized by law, if the developer claims that such actions are necessary to provide the 20% low and moderate-income housing units. A developer may choose one of three impartial housing experts from a list prepared by the Planning Board and have the expert make recommendations, at the expense of the developer, on the necessity for the proposed waivers, modifications or other actions. The expert shall also consider whether the requirement for which the waiver or modification is sought is a necessary minimum standard required for public health and safety. In the event that the expert determines that, even after full municipal cooperation, it is not economically feasible for the developer to provide the full amount of affordable low and moderate-income units, the expert may recommend that the developer provide 12% moderate income and 8% low-income units. Such a modification in the low and moderate income obligations shall not be approved unless the expert determines that the Township has substantially complied with his recommendations for municipal actions to reduce costs. The Planning Board shall not be bound to accept or approve the recommendations of the expert, but may in its discretion reject any or all of such recommendations. In the event that the Planning Board declines to accept one or more of the recommendations of the expert, it shall detail its reasons in writing.