We Support 7 different dictionaries. 4x4, 5x5, 6x6 and 7x7 can have a maximum of 1000 markers, The original dictionary supports upto 1024 markers, apriltag_36h11 can have upto 587 markers, and apriltag_25h9 can have upto 35 markers.
How to choose the bits of charuco dictionary?
The more the number of markers/corners, the better the accuracy of your calibration, but your camera should be able to identify your board correctly . So consider the camera's resolution, the target's distance from the camera, and the environment around you while choosing the dictionary to get a clear image and more corners.
while having multiple target avoid using 4x4 as it has been observed to provide ghost points due to its relatively simple pattern.