I was afraid of that. Removing it to test would seem like setting a house on fire to see if the whole thing will burn. :) I was told by an 'authority' that it would likely break the Lawson payroll applications if we removed it.
Our hosting company believes they have a way to test without actually removing the BSI application and we are trying that. However I question whether BSI has the right to force us to break non-tax-related functionality on our system to remove their application, especially since we've not been downloading updates so the tax calculations would not be usable anyhow.