I’ve not yet implemented support for those parcellations in my own tools yet (though have been meaning to do so for a long time).
It seems that if you’re doing a volumetric registration, there is already such a file. So I’m assuming you’re doing a surface-based projection, and are therefore getting an image containing values according to this LUT. In that case it’s not only a matter of making the indices within the existing LUT increase sequentially from 1, but also removing entries in that LUT that you do not with to be present in the connectome (e.g. ventricles). The LUTs I’ve produced myself and included in
share/mrtrix3/labelconvert/ have simply been done the laborious way. While it might be quite a drag to produce such, it does better facilitate interrogation of the connectome having direct correspondence between rows / columns of the matrix data and the entries in the LUT.
Also, if you do go to that effort, it faciliates the opportunity to contribute them to the MRtrix3 repository for others to use, and get recognition for your efforts