Optimizing the size of the pdf file

Hello dear friends.
Tell me please. The question is about the size of pdf files. The first few books, as well as their articles, were downloaded without size optimization, a 9-page file - 2MB, after optimization, such a pdf file weighs 180kb, which will significantly speed up the download. Each article consists of 3 pdf files, can I replace them with identical (in name and content) but optimized in size without any consequences. By consequences, I mean refusal to index or any other negative influence. I do not consider the possibility of re-adding journals since they already have DOI assigned.
Thanks in advance for your answers!

Can you test this on testing environment?

ghostscript -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/printer -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf 91-89-PB.pdf
mv 91-89-PB.pdf 91-89-PB.pdf.back
mv output.pdf 91-89-PB.pdf