If traits are not a viable option due to the vastness of the area and inconsistent symptoms, perhaps a more suitable choice for The Sims team would be to introduce playable items such as fidget toys. This could be a better approach. What do you think of that as an idea?
I would love a disability pack. The team started to introduce aids for a couple of disabilities but then stopped.
I know it's not the complete solution, but the creator thatonegreenleaf has made some pretty good CC of a prosthetic leg. You can find it on their Patreon page.