Hi Isbram,
thanks - this helps. So reading the GPKG results in GPlates displaying all attributes as they would display in QGIS by the sounds of it. Can you try and export as OGR-GMT files and check whether your attributes persist in those files? I also realised that there’s no GPML or GPKG export option… apologies.
It might be good to minimise the amount of extra layers in your project as -like you wrote- GPlates will add extra columns to capture names of additional files in the reconstruction. Then I also see that there are things like Lat and Lon (captured by the geometry, not necessary as attributes) in the attributes of your input file as well as doubled up ones likeFROMAGE_2 TOAGE_2 and others which could help bring down the total number of columns in the input data.
Other than that I don’t really have different suggestions. This might be something that happens in the code where @john.cannon would have to chip in. One test would be to try the whole workflow in pyGPlates and check whether the same problem persists.
What happens if you go the Feature Manager window (ctrl + m) and save your file in a different format? Do you see the attribute truncation there as well?
A lot depends on your post-reconstruction processing - given that this currently looks like a GPlates-internal limitation, I would just try and cut down the attributes to the ones you strictly require for the processing done after reconstruction.
Cheers,
Christian