Thank you for writing us.
I am unsure if that specific head unit displays TE and PS. However, I think you're on the right path. I believe there are some limitations with certain models of Garmin. I would contact them directly to be sure.
With that to say, it could be that the InfoCrank is not on the latest firmware to receive TE and PS. Can you write me at firstname.lastname@example.org and we can dialog in further detail about this? I specifically would like to know when the crank was purchase and where from. This way I will know whether TE and PS is accessed. If a firmware update is needed I can work with you and/or your athlete to get it up to date.
Hope to hear from you soon.