You will still have the Add to cart button but without the q-ty input. There is no way to show the q-ty and hide variations because the system does not allow to add to cart if the variation is not chosen, if you change the q-ty some variation may not have 2 or 3 products in stock for this variation and you’ll get the error. So, it’s not a good idea to hide variations for the mobile only. Either disable it for both using Theme Options > WooCommerce > Shop elements > Variation swatches > display on grid > off. Or show it for both.
