GPT2 model uses hardcoded 5° step
The GPT2 model cannot load grids with finer or coarser step sizes than an hardcoded value of 5°. As the grids include the latitude/longitude values, they could theoretically be loaded with a different step size. Indeed, tuwien does provide at least to step sizes: 1° and 5°.
To upload designs, you'll need to enable LFS. More information