Are there any particularly helpful examples or precedent processes of having restrictive covenants lifted or lessened in the USA (specifically Ohio) when a property is still owned by the original land developer (ie, a real estate lot in a subdivision has not yet been sold and is still and will remain, in perpetuity, held by the original subdivision creator)?
when a property is still owned by the original land developer (ie, a real estate lot in a subdivision has not yet been sold and is still and will remain, in perpetuity, held by the original subdivision creator)
Generally speaking, an owner of all property subject to the covenant or restriction can unilaterally change that covenant or restriction by recording a duly recorded amendment to the original in a manner consistent with any amendment process in the original in the real property records.
The main limitation is that often the existence of certain covenants is a condition imposed by a local zoning and land use regulation authority (usually a municipality, but sometimes a county or some other local government), and modifying the covenant or restriction without the consent of the body that insisted upon it for a favorable land use ruling or approval may revoke that approval if the covenant or restriction is modified without their consent or permission (ideally in writing and in official minutes of the government body).
For example, suppose that to get zoning approval to put duplexes in a subdivision after the zoning board of the city where the property is located insisted that the developer impose a covenant requiring the non-development of a portion of the land that forms a critical wetlands habitat, or that is necessary for the proper drainage of neighboring properties. If the developer unilaterally removed that conservation easement after receiving this approval, this would likely invalidate the subdivision approval and could cause the development project to be shut down or the city to obtain an injunction or declaratory judgment invalidating the change in the covenant.