I'm curious. Are you concerned about the fact moving the insertion point of a block may cause existing references to shift postion?
For example, I think you can change the insertion point of a block in 2006 or later using the block editor. Select all and move. But that will not change the Origin property of the block defintion. It remains (0.0 0.0 0.0).
IOW, to change the insertion point of a definition without affecting existing references, you would want to change the Origin property of the definition.