Displaying TPX storage is done via TPXOPER D STOR and D STORXA. Can we display the TPX storage via an MVS modify command (such as F TPX, D STOR) so the storage would show up in the JESMSGLG DD?
You cannot issue TPX storage commands from a console.
The TPX Operator Guide (TPXOPER) has a section "Commands That Can Be Issued Only From an Operator Session":
The following commands can be issued only from the Operator session; they can not be issued from the system console:
To set up an OPENGATE user to monitor storage