Hello,
By default, the Gantt chart is exported within one page regardless of the sizes.
It is possible to split it into multiple pages with the height parameter.
However, the PDF export is made by Electron.js, so there is no easy solution to control how it cuts the pages and move part of the content to the following page.
It is possible to display the scales on each page, but in that case, you won’t see some task rows:
The situation with the custom footer and header should be the same: you can display it on each page, but it will hide some task rows.
Right now, there is no solution for that.
I remember that someone else experimented with the DOM structure:
And I made the following snippet basing on that approach, but the tasks are still cut in the middle: