Your pony is also getting older, less courteous. Other then spending more time with him and playing with him, Grooming him there’s not much more you can do. Does he drive at all? Perhaps you can have s9me fun with carting, older horses and pony can do this easily as there’s no weight on their backs and most love doing this vs riding.
When my mare turned thirty we switched to a small jog cart, she was thrilled to go out on trails once again she loved being by the lake and woods instead of the paddock and cornfield. Whole she could just jog a little bit and walk we still enjoyed each other’s company. Some of her old spark returned as she got back into better condition from the very short rides we used to do before. Once again I would find her at my front door, having unlocked her box and wandering into the yard saying let’s go you sleepy head. Although it wasn’t daily driving it was three times a week and I would brush her down daily. Horses do have a close bond with their humsns if they spend enough quality time with them,