Hi so you had 2 items here with the ping page.
First removal second adding information.
For Removal its pretty easy you can do this without a lot of customization.
I have myself made a service "MyPingPage" on the gateway to call the ping page. And in my service I used a regex to only put what I want returned in a return template response to requester.
For the addition of data I dont know of a "Supported" approach to doing this. Though I do know for most of the data it calls a .sh on the appliance. And in theory you can modify this script. But I would prefer for sup-portability that there is no modification to it. So it might help if you want to expound upon what you are trying to accomplish, so we can determine if there is another better supported way to get it.
But it would be easy to build a /ssg/myping page,
And just remove the contents of, "I want to remove let's say build version" in this method without making any modifications to the default script itself. And returning a response with only the data you want provided.
Charlie.