I would need a bit more information to make sure I give the best advice, since you are focusing on agricultural land only, I’m guessing you’re not doing land-cover but some other usecase and the approach shown in this notebook might not be the most suitable one for you.
It i possible to provide the polygon-layer instead of the country shape and the eopatches will then cover only areas where there is some polygons intersecting the bboxes. If bboxes have too much empty space, you can even decrease the size of the bbox to fit them better to the distribution of polygons.
I would point you to this location in the examples where you can see a similar thing being done, which is also used in the eo-learn LC example: https://nbviewer.jupyter.org/github/sentinel-hub/sentinelhub-py/blob/master/examples/large_area_utilities.ipynb#Splitting-into-UTM-grid-zones
Let us know if this helps or if you need further assistance!