Last night I switched the method through which I import my mastodon toots from here into my #11ty blog.
It now pulls changes when a ci build is triggered using an external script, rather than during the render/build phase. It does this by generating markdown files with yaml frontmatter. The process creates a new commit which in turn triggers a full build of the site on the main branch.
This means that my content, or at least part of it, is still available if I need to migrate instances again.
I need to further refine the process, as media and emoji are hot linked. This was not my preference but I could not get my head around async await at 2am.