Form handling differences

I am using a standard setup of WordPress, WooCommerce and Storefront theme. I am now trying to optimize the registration process and I stumpled upon some differences between the regular user registration form (my account) and the form during the checkout process.

Could somebody help me to understand these differences? During the checkout process, I get a nice JS form evaluation and double opt-in email options, whereas these features are missing in the regular my account user registration form.

Thanks!