Validating the CVV field in Spreedly Iframe v1

I am using Iframe v1 to integrate spreedly payments into my site. I tried to use the setRequiredAttribute method to make the CVV field mandatory, preventing customers from completing a payment without providing a CVV. However, it's not working as intended. 

I understand that I can check if the CVV is empty using the `verification_value` data. However, I'm unsure how to validate if the user has entered a 2-digit CVV. Is there a way to set the minimum length for the CVV field to 3 digits? 

Please share any workarounds or solutions for this issue. Also, do your other services like Express form work similarly or do they validate the CVV minimum length, I checked this in your sample site, and it was validating the CVV length in the Express form.