Endpoint Manager Display Name and Extensions with Grandstream phones

I upgraded to freepbx (latest) from an old trixboxce installation. I purchased the endpoint manager module to make it easy to configure my older grandstream phones (gxp2020, which I use the gxp2000 configs for).

On the old trixboxce system, the line key would display the extension number, then in the large LCD, display name area, the “Name” (the user’s/extension’s “Display Name”) of the extension would show.

With freepbx (and endpoint manager), I can choose the “Line Label” to be either the display “name” or the “extension”. When I do that, both the areas of the grandstream phone are set to Name or Extension number.

I would like to have extension number display in the Line Label area, and the Display Name display in center of the screen.
How should I go about doing this?