Ohio Rev. Code Ann. § 303.34

A county renewal plan may be modified at any time. If such a plan is modified after the lease or sale by the county of real property in the county renewal area, such modification may be conditioned upon such approval of the owner, lessee, or successor in interest as the board of county commissioners may deem advisable, and in any event shall be subject to such rights at law or in equity as a lessee or purchaser, or his successor or successors in interest, may be entitled to assert.