Instead of hardcoding a value, calculate the maximum zoomlevel in which there is still an increase in detail. By using the configured orthophoto resolution or GSD.
The higher the latitude, the higher the resolution will be of the tile.
Resulting in a chance of generating useless tiles, as there is no compensation for this.
At the moment it'll use the worst-case resolution from the equator.
Zoom level calulation from: https://wiki.openstreetmap.org/wiki/Zoom_levels