Hi,
That is true.
If you need both then use the codes
if(empty($this->element->main->product_name)){echo $this->element->product_name;}else{ echo $this->element->main->product_name; }
and:
if(empty($this->element->main->product_name)){echo $variant->product_name;}else{ echo $this->element->main->product_name; }
For version 1.4.1, we will add an option to generate or not the variant name with characteristics. But that will apply everywhere.
If you need to have a specific name for your variants, you can just edit them and set a name... That will disable the name generation and use the name you set in your variants.