Hi,
It is possible to do it.
You just have to add an onclick on the country field to auto submit the current block when changed.
To do that,
You want to change the line:
'class="hkform-control" '.$onWhat.'="window.hikashop.toggleField(this.value,\''.$fieldName.'\',\'address_shipping_' . $this->step . '_' . $this->module_position.'\',0,\'hikashop_\');"',
in the file sub_block_login_registration.php via the menu Display>Views to something like that:
'class="hkform-control" '.$onWhat.'="'.($fieldName =='address_country' ? 'window.checkout.submitLogin('.$this->step.', '.$this->module_position.', \'register\')' : 'window.hikashop.toggleField(this.value,\''.$fieldName.'\',\'address_shipping_' . $this->step . '_' . $this->module_position.'\',0,\'hikashop_\');').'"',
That will automatically register (or validate the guest form if you're in guest mode) of the user and refresh the shipping area with the corresponding shipping methods when the customer selects his shipping address country.
But we can't do that by default. In most cases merchants don't want the registration form to validate when changing the country as the state needs to be selected after the country selection.