Quit add to cart button WITHOUT activating catalogue option

Hi,

There is no option to disable the add to cart buttons on the product details page.
There is only an option to disable the add to cart buttons on the listings (in the menu item settings or the module settings ), and the setting in the configuration is just the value for when you select "inherit" in these menu item/module settings.
So I'm afraid that you can do it with just the options available. You'll have to modify a bit the code with a view override.
Since you can already control the add to cart button display for the listing, you just need to edit the view file product / quantity.php via the menu Display>Views to control the display of the add to cart button on the product page.
You'll find there this line:

$catalogue_mode = $this->config->get('catalogue', false) || !$this->params->get('add_to_cart', 1);