Yes, there are sometimes different names for parameters in the command line tools for various reasons. They are all documented in the appendix of the Quick vignette.

If you used the command line tools, then you likely set --maxcopynumber to a high value. This specifies the range of tested integer copy numbers. The difference between two consecutive integer states becomes very small with increasing copy number. In average clinical samples, you cannot distinguish 7 from 8 copies anymore. In high quality, high purity, you maybe can, but 8 and 9 becomes pretty much impossible. 

As documented, that does not mean PureCN does not accurately call amplifications with higher copy number. Everything that does not fit the tested integer numbers will be simply reported as non-integers.