The short answer is really quite simple - the Agreement Regarding Development has no effect on the equestrian center property whatsoever.

The following excerpt from an August 31, 2018 letter from attorney Larry Oldham to the CRC HOA's attorney, Kimberly Gaddis, in response to her July 19, 2018 letter to Mommies Properties' attorney, Stuart Teague, discusses what the relevant issues pertaining to the Agreement Regarding Development:

"...I share your opinion that the Agreement Regarding Development (the "ARD") between Bentwood Stables, LLC, and Linda Allen dated December 21, 2000 and recorded October 18, 2007 at Deed Book 4929, Page 130, aforesaid records affected the use of the Mommies Property by Ms. Allen and her successors-in-title. You appear to have argued at some point that the duration of the ARD is perpetual although it is clear from a review of the ARD that it was intended to continue only through and including December 21, 2016. Notwithstanding any dispute regarding the ARD's duration, if the ARD were in the Mommies' chain of title, Mommies would have had constructive notice of same and it clearly would have governed Mommies' use of the Property. Similarly, if Mommies or any of its representatives had actual knowledge of the existence of the ARD at the time Mommies acquired the Property, its terms and conditions would bind the Mommies Property.

As a matter of fact, however, no one at Mommies had any knowledge about the ARD until fairly recently and it was completely out of the chain of title to the Mommies Property at the time of Mommies' acquisition of it, and that is what Mr. Bose represented to the Association and its members in the mass mailing that he sent in March. Unless the Association or its members can offer some proof that same is not the case, both of us should be able to agree that under Georgia law, the ARD does not bind the Property at all since it was not in the chain of title when Mommies acquired the Mommies Property. We recognize that the one thing that is missing at this point are appropriate Affidavits regarding the knowledge issue and we plan to record Affidavits of Title in the chain of title to confirm that no one connected with Mommies had any actual knowledge of the existence of the ARD at the time Mommies acquired the Mommies Property.

As mentioned above, even if the ARD somehow bound the Mommies Property at the time it was filed, the obligation of the property owner to maintain and use it solely as an equestrian center terminated on December 21, 2016, as did all of the other terms and conditions contained therein that related to the operation of the equestrian center or to the maintenance of stalls for the residents of the Chattahoochee River Club. Nevertheless, you indicated in your letter that "...the horse trails identified as running through the property as evidenced on the plat/survey attached to this document at Deed Book 4929, Page 133, and the Public Access Easements (connecting to the horse trails in the Association and in the CRNRA) do NOT expressly expire by terms of the document...." I presume that reference is to the quintessential "Nature Trail to Nowhere" depicted as "20' Access Easement for Nature Trail Use" that appears as the fourth recorded page of the ARD but is not referenced therein at all and is not included in any easement granting language contained therein because there is none. To the extent it actually exists, the Nature Trail to Nowhere apparently ends at the property line between the Mommies Property and the next door neighbor, dead-ends into the swamp and ends up on the gravel road depicted on the picture. [U]nder the Association's theory, [the next door neighbor] is required, along with adjoining neighbors, to allow horse access through their back yards to who knows where else in the development...."