orthophoto_resolution has a default value of 5. Lowering it will increase quality/sharpness. For very detailed, I go as low as 0.5. Lowering this value will add additional time to processing and can be a lot compared to default.
It is lower (probably usually) lower. It is defined in ODM/opendm/tiles in the generate_tiles definition as generating tiles from 5-21.
I would open an issue here requesting additional zoom depth:
I tend to generate tiles to 22 or 23 for drones, but it’s a good discussion to have. Alternatively, we could use the GSD calculation to choose the zoom depth, which might be the more correct way to do it.