The problem is, someone out there isn't doing at least one of the above suggestions (or others that I've forgotten), or someone will intercept the original input while it's in flight (no one uses unencrypted connections on open public wifi, right?) or make use of some other arbitrary way that passwords can currently get stolen. And once they get that original digital representation of your typing style, you're done. That method will never be secure for you again for any service, unless you spend the time to change your typing style (and remember your new style should not be at all predictable to someone who knows your old style).
It's an equal certainty that there'll be implementations around for as long as humans remain that stupidly include un-hashed authentication data.
It might be possible to have the server randomly choose what text to test your style on. That would also solve the secure storage. But it's a very hard problem.