Categories are used to group people with like locations, or something else in common. The problem I see with what you've done, would be ok if it was only one category. But if you create a category for each profile you research, (because you've named it very specifically) you're creating hundreds of categories.
A space page like Doug suggested would work just fine. I would just make one, and keep sections for the profiles, I was researching.
One Wikitree-er starts right on the profile with a big section labeled
=== Temporary Research Notes ===
When she gets enough facts and sources to write a bio, everything is at her fingertips.
If you don't want random folks seeing you're idle notes to yourself, type <!-- at the beginning and then at the end add --> Everything inside the arrows is hidden from the public and private view. These notes only show in the edit view.