What if I want to source my new releases more effectively by focusing all my bandwidth to only my upcoming releases. ... De-select the extra shared directories in the "All directories" drop-down category?
Uh-oh, that might be the problem.
Do not do it that way.
I THOUGHT I had a clever but complicated technique involving the files in the Emule/Config folder, but when I went to test it, I was unable to force my eMule to have to slowly rehash files! I temporarily unshared hundreds of files, then afterwards reshared them without having to rehash all of them. I even did it again, and shut down emule in between. Still no need to rehash. So if I can't replicate the problem I can't test my solution.
SO TRY THIS INSTEAD ---
This is how I temporarily share and unshare files. I had not done it in awhile. I do not unshare individual files because that will force it to rehash later, I do it by directories.
1) First, keep your shared files in multiple shared folders. That way you can move files from one folder to another while still keeping them shared.
2) You can add more folders to share by first making the empty folder, and then sharing it in emule in Options/Directories. Click the folders you want to share and then Apply + OK. Note, incoming and temp stay shared by default even if they are not clicked. See mine below:
Options shared.jpg
3) Name the folders in any way you want. I have both archived My Releases or Other people's Releases, a folder just for subtitles that I am always sharing because they are small, and newer files by month. The newer files get deleted as I need space.
4) When you want to have just a small number of files be the only ones shared, put JUST THOSE FILES in their own Shared folder. You could call it "My New Releases". If those files are already shared in a different folder, then make sure you make the My New Releases folder a Shared Directory before you move the files. That way those files stay hashed.
5) After the files are shared in "My New Releases", go to Options/Directories and UNCLICK all the folders that contain the files you want to temporarily stop sharing. Then click Apply + OK. In this image I am just sharing "My files":
Options unshared.jpg
6) When you want to go back to sharing the other folders, Click them in Options/Directories and then Apply + OK. If all goes well then they should quickly be reshared.
NOW ... I do NOT guarantee that you will never have to rehash, but so far this method seems to work for me. I seldom unshare files except by deleting them from my onboard drive to make space, so my memory of the reliability of the temporary method for avoiding rehashing is fuzzy at best. If for some reason you end up having to rehash for hours, post again in this thread to spread the bad news.