You could either make a for loop to check in an existing array of point to see wether the point you’re creating is within a radius of already existing points.
Or another idea would be to base you scatter on a procedural noise texture instead of a random in bounding box. But I’m not sure exactly how it would work, maybe start at points with value 1, then 0.94 and so on. The increment mixed with noise frequency would kind of be your min distance beetween points.
Or use a custom scatter .otl tool from houdini with houdini engine for unreal ?