Thanks for your request.
It is not possible to use a soundcard with a 2.8″ touch display.
It is possible to use more than one soundcard. It is also possible to use a usb dac and a 2.8″ touch display.
Or you take the >>> original Raspberry Pi 7″ touch display from our shop <<<. This touch screen is not connected with the gpio pins as you can see >>here<<. (it is a possible setup with the Raspberry Pi, the touch screen and a HifiBerry sound card)