Thanks for the recommendation.
However, after installating the plugin the whole site crashed completely.
Thus, I went on with kirby’s built in cache.
What I noticed further: With so many subpages, not only the pages that make us of those subpages when rendering are slow, but every page of the site slows down. Also the load times in the panel increase dramatically. Is that a known issue or more like a problem on my end?
When you filter such a large collection, kirby has to read every single text file to find the right item, so without caching, this will slow down your site.
feel free to create an issue at my boost repo if you want me to help you set it up properly.
my guess is that you used v2 (zip from main branch) which is not really stable yet. please try again with the release zip 1.9.x
i fixed my repo in creating a separate branch for unstable development since it will take a while before my v2 will be released. the plugins main branch has been reset to v1.9.0 so readme and installation via zip/git-submodule/composer should work again properly.