So I think it is clear, based on what everyone has suggested, that in this instance it is best to store documents externally and export when needed.
Now the thing is, I'd like to open the document in the temp folder (still not exactly familiar with this). The reasoning of course, is to avoid having copies made on the user's desktop.
I now have a button to "update" the portal row. This will insert the selected file back into the container field thereby overwriting the older version.
I have 4 questions.
1. how to indicate to FM to export contents to the temp folder.
2. how to allow the user to update the container with the new version if it is stored in the temp folder (i.e. how would he navigate to that folder).
3. is there way to avoid having the user indicate which file to update back into the container field, and just have FM insert the contents of the temp folder back into the container.
4. can this method work for WD and FMGo as well as desktop.