Unless someone is redefining the definitions of "balance" and "boost" there is no similarity between the two. Balance meaning to have equal force about a pivot point, boost being an augment to the applied force. In fact, most boost tabs will be counteracting to balance as they usually contribute more static unbalance to the assembly as they are adding mass aft of the hinge or pivot point. There is also a difference between static and aerodynamic balance and either one or both can be accomplished with different implementation of structure. For instance, static and aerodynamic balance can be obtained by properly weighting the area ahead of the hinge line where that type of balance is implemented.