As a Roblox developer, it is currently impossible to limit the maximum render distance (with the hardwired MRD being the limit). I know I sound crazy requesting for a setting to decrease the MRD, but my game would actually greatly benefit from faster performance in a defined spherical area and a mechanic to hide objects without having to change their transparency or parent.
You may have seen games that use “bubble/planet maps” that teleport players between map chunks across the Workspace in inverted spheres, I believe Hexaria still utilizes this technique, and my game essentially works in the same way. These games don’t require a far render distance but objects within the hardwired MRD would still be taken into account of rendering. I also mentioned a mechanic to deliberately not render objects based on distance because my game cannot use local skyboxes and I would like to keep everything in the game as close to the center of the Workspace as possible (and thus each other) to maximize physics efficiency.