An alternative that works very well for signatures too is Perfect Freehand (by the guy behind TLDRaw) https://perfect-freehand-example.vercel.app/
Is it allowed to modify the signature someone puts digitally on a document? Because that's what this does. Is that not an issue?
You may find users who get mad if your settings are too aggressive though, and if they're unable to get a signature that they approve of.