I usually do some clean up in Affinity Designer before I import - either PDFs I convert or files I get from a client.
Still tedious, but I can somewhat quickly get a lot of the hatches and stuff selected and deleted.
Deleting Tags and their associated geometry is also useful.
I wish there was a plugin to select geometry of a certain size - length range for lines and area for surfaces. Would make quick(er) work of this process.