Yes, I tried and it went rather unexpectedly - the framerate dropped to around 15. Without the setting it floats around 40 in cockpit view, and surprisingly, around 30 when viewing the map (when selecting a mission).
45 FPS is more or less comfortable, but still, I would expect more from my system.
Update: The game was running in Windows 98/Me compatibility mode, which I disabled and tried enabling TnL again. Now it runs smoothly at 60 FPS.
Last edited by Vshining; 08/19/19 11:57 PM.