If I use --annotations flatten, how does it affect the size of the xod? Am I more likely to run into out of memory problems in the browser?
Would it effect all xod’s that I use this option for? Or only xod’s that were created from pdf’s that have annotations?
It will not likely make a significant difference to the file size or browser memory. The main difference you will run into is that since the annotations are flattened the visual appearance will be correct, but you will not be able to edit those annotations. Popups will also not show because they are free-floating. This flatten behaviour is essentially what ToXod conversion used to do by default.
We are currently in the process of adding support in the viewers for a number of annotation types for the case where --annotations flatten is not used.
–annotations flatten will only affect XOD files created from PDF files with annotations.