PDF Space Export in large spaces

We have a space that is our knowledgebase and contains close to a thousand pages and attachments.

We want to move a large portion to other spaces; but, cannot because of other Atlassian bugs that have issues maintaining link references and lose attachments. So, we're stuck keeping all of this content in this one space until these issues are resolved. Had we known that Confluence cannot handle large documentation spaces, we would have set it up differently. But, here we are.

We use our knowledgebase to generate our customer facing and any other external facing documentation. But, to export more than one page (e.g. usually is a module that has a couple of parent pages and then all their descendents), we have to use the custom space export. We also have to use this because it is the only option provided to have footers and headers for all pages.

Unfortunately, due to volume, that option has become unusable. It takes approximately 5 minutes to even render a page when selecting the option. Then, when you select Custom Export, it takes another 5 minutes because the solution renders ALL PAGES, ALL Expanded....

We want to be able to get to our hierarchy and then display the children upon request = similar to our sidebar where we retrieve upon request.

We need a solution to help improve the performance of just trying to create a custom export; and then, address the issues of how long it takes to generate and download.

Right now, our users are getting very frustrated with the performance.

We would appreciate advice on how to resolve.