Hello,
What are the PDF export settings? The publication must have settings that may be useless and weigh down your PDF. Do exported PDFs have images? Are they optimized in size and weight?
In addition, I always use automator to optimize my heavy PDFs. it is an application included in MacOS that automates to can ready all tasks repulsive.
Christophe - FRANCEArchicad Designer and Teacher
Archicad 15 to 27 FRA FULL
OS 11.6 Big Sur - MacBook Pro 2017 - 16Go RAM
"Quality is never an accident ; it's always the result of an intelligent effort" John Ruskin