But the CLS aircraft is natively recognized ...
Not if you merged it.
Is there any way I could use these config data ?
It shouldn't take more than a few minutes to create a config file from scratch for any airplane, using the new editor.
However, if you really find it so difficult to use (it shouldn't), you can try to revert to a pre-merged configuration (the stock CLS), open the editor on that one, and SAVE a GSX.CFG for it, without doing anything. Then, go to the %APPDATA%\Virtuali\Airplanes folder, look for the GSX.CFG that has just been created, and there you have the data you will need to copy&paste from this GSX.CFG to a new one you'll create with the merged config.