Sam,
We do reduce the "device rendered" tower graphics on the Sectional based on alert status and zoom level because the sectional already has them represented, for the most part. If you are being alerted of a Tower, then it should show up and be highlighted on the sectional. Vector mode shows a more exhaustive image of towers being rendered by the device. We also show the Tower Obstructions in the Vertical Profile instrument. I hope this helps.