I removed and then added a new Exclude folder to my index, and it seems like Everything 1.5a is rebuilding my entire index of 200Tb of content, including the properties I wanted indexed as well
Is this expected? Are there other things like this that can cause a reindex?
The content and properties should still be indexed.
You should be able to search and view all your index content and properties after changing your exclude options.
Changing the exclude settings can trigger Everything to refresh all content and properties in the background.
I will improve this behavior in a future version of Everything.