I want to see the downvotes on my posts, which makes me wonder if it’s worth deleting my current Lemmy account and creating a new one on a server that allows downvotes.
Sounds like you’ve answered the question.
The problem is that I don’t know if it’s worth it.
You don’t have to delete your account unless you want to free up the name for someone else.
Making an account on another instance to try it won’t hurt anything.
… And you won’t know unless you try. It’s not etched in stone or anything. It takes 5 minutes to set up and account, and about the same to delete one. Pick an instance, sign up and use it for a day or so, then make a decision. Not that hard.
Seems like you should just create the new account and decide whether you want to delete the old account later. Nothing wrong with having accounts on multiple servers at the same time.