Random ideas for this:

• with CONFLUENCE-188, it might be possible to also avoid reading the some of the objects to ignore.
• ConfluenceInputFilterStream could provide an EnumSet or something similarly efficient to ConfluenceXMLPackage of objects types to ignore (deny list) or to enable (allow list). This might be a low hanging fruit. However, one should make sure added tests to check whether an object should be imported don't slow down full imports too much. Notably:
  • ContentBody objects can be safely ignored if content import is disabled
  • Space permission, content permissions and permissions set can be safely ignored if right import is disabled
  • maybe InternalUser and InternalGroup objects can be ignored if user and group imports are disabled, but one needs to check that this doesn't have side effect. It shouldn't, many confluence migrations are run from space export packages, which don't contain these objects to my knowledge.
  • BlogPost objects can be disabled when blog import is disabled.