It may be more than balancing. wheel, material, machine, and method.
Some times a weight added to the wheelhead can help on a small grinder grinding harder material, but you don't want to keep it there because it adds wear to the down feed works.
Some small machines can have a better cross direction.
QU: (Front edge is chamfered by 30°] the lead edge will chamfer itself as needed, Hand doing this can be detrimental.
The forces of grinding can tend to pull/push the wheel head to take up and wheel head clearance to one side or to forward and back. temporary use of a food spring can alive this problem, again continued use will add wear to a machine.
Some tines one-way long feed can help, to cross feed off the part and then travem only in the grind direction. for most grinders this is making grind sparke only traveling to the right.