The access denied error will occur when attempting to secure a print queue who's driver is a v4 driver. v4 drivers do not support the use of 3rd party port monitors and are therefore incompatible with the Blueprint Enterprise environment. The standard Windows class driver within Windows 2012 is a v4 driver, which explains why you experienced the permissions error. Most commercially available manufacture provided print drivers are v3 drivers, which do support 3rd party port monitors and can be successfully secured within Blueprint.
Thank you for the reply, Tim!