Without C++ access, the ini file is the only way to change the near clip plane. Can you change it in any other *Engine.ini files? For example, do you have that line in you MyGameEngine.ini file?
The reason for the clipping plane is the way the depth buffer works. Depth is calculated with more precision the closer the object is to the camera. Once the object is far away, the engine makes very rough estimates of depth. That often isn’t a problem with static meshes, but decals can get very messed up if the engine doesn’t get their depth right. Setting a near clipping plane moves the depth buffer out farther. Usually if it’s just a few Unreal Units, there’s no noticeable difference. But with my game, where the camera can be thousands of UUs away from the action, I need to control the near clipping plane.
If you’re certain you can’t change the near clipping plane in the ini files, then you’ll probably need a workaround. Maybe put the camera a little farther away and decrease the field of view a little more.