CheckoutWC includes built-in support for WooCommerce - MailerLite.
When MailerLite is activated with CheckoutWC, the newsletter subscribe checkbox will always show up right under the email field. (Specifically below the 'Create a shopping account' checkbox if present)
If you would like to not have a visible checkbox, you can set the checkbox to hidden in MailerLite settings.
It's important to note that the Position setting is completely ignored when CheckoutWC is activated. The checkbox will always be added beneath the email field.