A silent version that can be called from a batch file using a parameter to either enable or disable doubling as desired (just run it with the right parameter for the desired config, it will not produce duplicate ini entries, so don't worry about that). File is attached, including the silent executable, the NSIS script and example batch files.
Usage:
to disable warp doubling:
SilentDoubling.exe /DOUBLING=disable
to enable warp doubling:
SilentDoubling.exe /DOUBLING=enable
to override the OP installation folder detected from the registry use the /D parameter (disabling warp doubling in this example):
SilentDoubling.exe /DOUBLING=disable /D=C:\Program Files\Foo
I have not tested this function though and am not sure if it can use relative paths. NSIS says not to put it in quotes even if there are spaces in the path. The script detects the OP installation folder from the registry which will be correct in all cases anyway, unless the user has multiple OP installs and is running OP from a folder other than the one it was last installed to... (I really wish people wouldn't do that - its so much simpler to make copies of the folder and cycle them through the actual install location indicated in the registry by renaming the folders.) But I would welcome feedback if anyone is willing to test the /D parameter using relative paths, if that works then this is not really an issue for batch installers.