Editing a few strings in the PList won't add support for the G25/G27. Yes it'll (maybe) let the LogitechHIDDevice take control of it, rather than the generic HID in OS X, but the driver still won't know what to do with the G25.. and will likely simply fail to load.
I don't think you understand the complexity of a driver, it's not something that "hacking a plist" can fix. It would need to be entirely rewritten, for the G25 a control panel would be written as well, to send commands to the device to set rotation, combined/seperate pedals and such.
Yes, Logitech could write a kext for the G25, but they won't. The LogitechHIDDevices.kext - which I don't even have in my OSX install.. only LogitechForceFeedback.kext.. which is written by Apple anyways - isn't something that could be hacked. It's not a matter of going in and saying "use G25" in the code. They need to effectively code the driver from scratch. Not to mention a random forum for another WINDOWS racing simulator isn't the place that will get any notice from Logitech.
And it's not the same for Linux either. The issue with Linux is most people using it aren't using it because they are forced to.. they are using it due to ideological (or stability) concerns.
Linux won't gain adoption becuase due to these ideological views of "go free software", binary drivers for GFX and other hardware is discouraged. Thus the average joe that installs Linux, won't have 3D support... It's something that every OS seems to take for granted. I install Windows 7, and I have basic 3D support.. I connect to internet, and it takes hold and installs proper drivers for me. Voila, I have full 3D support. OSX, it just works.
Nobody sees a market in Mac. Valve just tried the waters recently by porting Source games over, and has been met with a larger base than expected, but that's a variety of popular FPS games, Counterstrike, Half-Life 2, Team Fortress 2, and Day Of Defeat. CS alone has millions of people playing on any given day. LFS maybe has 10,000 people playing, so a port reaches say.. 30 people? Not a good return on months that Scawen may spend on it.
It's a futile topic to converse. Don't get me wrong, I'd be the first person to go "Yay Mac!" in a thread, but Scawen has waaay more things we'd all rather him work on than effectively rewriting the 3d Engine , Input handling and Sound engine of LFS.