I really dislike the whole signature comparison thing. Truly “handwriting analysts” are often hacks. They will say: 50-50.
We should not have signature verification as a part of voting. It’s too easy to forge a signature. A good forgery is great; a bad forgery will work too. It’s also easy to “deem” a signature as “substantially similar,” or “matching,” etc. And it’s too easy to throw boxes of ballots into the SF Bay. Signatures also change over time.
No signatures. Just voter ID and in person. The way to go.
Even credit card companies have moved away from signature verification for purchases.