Bug - Disabled Lastname setting is ignored in Checkout

Tried to setup a shop where customers enter their full names into one field to make it more compact, therefore I disabled the 'Lastname' field (and renamed the 'Firstname' field to 'full name' in the language resources)
But at the checkout (I tried it with the one-page-checkout only) the shop still asks for the Lastname.

Try "Clear cache"  (gear icon in admin upper right corner)

How did you disable Lastname ?
There are separate settings for Customer Registration details and Address Form Fields
See https://admin-demo.nopcommerce.com/Admin/Setting/CustomerUser
It does not appear to allow you to disable Last name for the address field

You are right, I could disable it only at 'Customer form fields' and there's no such setting in 'Address Form Fields', my bad, sorry.
Let's change this thread to a feature request then to allow the checkout process be less complicated, ie. one less fields to enter.