True
I think I recognized the issue with the Share menu.
The Share menu does work to share Rich Text files, Markdown files, and some other types but does not share PDF files, HTML files, and many others to OmniFocus.
I am guessing that the types of files which OmniFocus accepts via Share is set by the OmniFocus developers and I cannot change it. Correct? Or is there some other trick I can use to change that behavior?