Hi,
Here is the documentation of PayPal for the "no shipping" option:
Do not prompt buyers for a shipping address. Allowable values are:
0 – prompt for an address, but do not require one
1 – do not prompt for an address
2 – prompt for an address, and require one
The default is 0.
And for the "address override":
When you pass in address_override=1 or tax or shipping variables, PayPal displays the values in the payment widget. Also, PayPal hides the calculation widget, regardless of setting up shipping and tax rates in your Account Profile.
Also, for our explanations on these fields, just click on the "help" button at the top of the PayPal payment method settings page and it will display the help relative to these options.
HikaShop already sends the address data to PayPal, regardless of how you setup these options. However, PayPal will only use them if the "address override" setting is activated. So yes, that's a standard feature of PayPal.