I've noticed in recent months that some designers are really trying to push the visuals. This is always welcome IF performance is not seriously compromised. Frame rate drops will adversely impact real time mouse swingers due to the forced tempo calculation. As in any other game engine there are methods that should be used to optimize rendering in an open world level (golf course). Using an uncompressed 8192x8192 texture instantly allocates 256MB of VRAM at all times since it is mapped to the entire terrain. Foliage objects (Speedtree or other) should have proper LOD's setup and adjusted as needed. Also, the modular style buildings used on many courses are horrendous with flickering materials. Not only are these an eyesore also resource hungry with inherent seaming issues.
4096x4096 should be more than acceptable to blend the underlying color tones from the satellite image into terrain materials. I've long been a proponent of gameplay over glitz. In JNPG the impact of FPS drops on gameplay is a real killer and there is no excuse for it because performance can be optimized by the designer. Unity's Profiler tool will provide performance numbers for GPU/CPU/RAM/VRAM/Audio, etc. There are also general, performance related practices that can be followed to help reduce rendering loads.
*Note, the link below pertains to the 2018.x versions of Unity but still good guidelines to follow.
Lastly, a course designer should target mid range system specs if they want their course to be enjoyed by most players. If you have a beast of a system, take advantage of the Profiler tool for performance stats and optimize as needed.