AI, which isn't always accurate, offers this workaround. Worth testing...
"In NCH Disketch, it appears that reducing the size of the inner circle to align perfectly with the hole in the middle of a disc is not currently an available feature. Users have reported this limitation, noting that the software does not allow shrinking the inner circle to fully cover the printable area around the disc's center hole.
However, adjustments to the printable area and center alignment can be made in the Template Properties Panel. This allows for some customization of label dimensions, but it may not fully address the issue of resizing the inner circle to your desired specifications.
If this feature is critical for your project, you might consider submitting a suggestion to NCH Software through their feedback page, as they often incorporate user suggestions into future updates"