You are quite right.
You can use the preview option to scan more than 60 sheets, but it seems it must be the same size and orientation etc, and you cannot mix in pages scanned from the platen.
The build job feature on the larger format AltaLink allows you to change the original type / orientation / etc and allows scanning from the glass and the ADF mixed and matched in the same job.
I agree with the sentiment here, there really should be a build job feature on the VersaLink platform.