I know 1.5 had the framerate display enabled by default (never figured out how to modify that preference though). I don't know what Battlezone 98 Redux is based on but I would assume the same framecounter exists somewhere.

There no documentation? Command line parameters maybe?

From the Battlezone FAQ:

How Do I Get My FPS and Polygon Count? There should be a RENDER.cgf file or something like that in your Battlezone Directory. Op […]
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How Do I Get My FPS and Polygon Count?
There should be a RENDER.cgf file or something like that in your Battlezone Directory. Open up the file and you should see a line like this:

[Debug]
;TrackFPS = 1 //Display FPS and polygon count

To get your frames per second and polygon count simply erase or delete the ";" in front of the line. Now save and close the file and when you boot up a game of Battlezone it should list the info in the upper right hand corner of the screen. Remember that adjusting the Graphic option on the game will affect your frames per second so if it is really low and the game seems unplayable that is probably because you have too many settings such as textures on high.

The only render.cfg files are in Battleezone\video cards\

Upon opening Battleezone\video cards\3Dfx\render.cfg, I see only these lines,

1[d3d]
2
3triplebuffer=0

I added the following,

1[Debug]
2
3TrackFPS = 1

however the framerate did not appear on screen during gameplay.

From discussions that I have seen in other forums, it sounds like the render.cfg file needs to be in the Battlezone folder/directory. I'm guessing your setup did not create one (or it got deleted) somehow. That's the only thing I can think of, but the TrackFPS variable is what controls the FPS counter:

http://videoventure.org/battlezone/render_cfg_settings.html

What I had to do was create render.cfg and place it in the Battlezone directory. Then add,
[Debug]
TrackFPS=1

Works now. Thanks for your help!