I will also do what you suggest and maybe open an issue with pdf-tools.

I am a layperson, but the problem seems to be that the kind of buffer variable pdf tool creates doesn’t work if the files are big with whatever functions dired+ uses to handle those buffers whereas the functions for “go to dired buffer from pdf-tools buffer” that get called without dired+ installed do handle the pdf-tool buffers. So yeah, that could be just as easily be a problem either with the way pfd-tools creates the buffers or with how dired+ handles them. Dired+ works fine with everything else when jumping to dired.

Anyway, that was the thought process of a former English major.