I do not see how Callas can be used to specify preflight for a specific page. Another solution is to use the Split node. Split the job into 3 pieces (see below):
Select "Maintain sub job order" to ensure that when the sub-jobs are joined together, they are in the original order.
Off of the 2nd slit branch for page 2, apply the required "fixup".
Is there any way to preflight only specific pages in PDF?
Im makeing Fixup from Callas and I want to do this only to 2nd page.