I tried restoring the iPad as a new device, didn’t work too. So I had to go back to Apple Store Singapore and get another replacement iPad, forcing me to 11.4.1 from 11.3.1. Thankfully so far there are no issues but we will see.
Here’s some pointers from the staff that helped me with this case:
1. The iPad Pro is a pressure sensitive device. This is due to it having a pressure sensor under the screen. This means that you should avoid placing heavy weights on the iPad at all. One common mistake by some customers is to place the iPad on the backmost area of their backpacks (e.g. at the compartment that is also meant for paperwork) and then having the backpack placed such that this area is being pressed down by other content of the bags, which exert undue stress on the iPad and eventually making the screen too close to the pressure sensor, leading to these phantom touches. Having proper pads around the iPad like a sleeve will help mitigate this. Alternatively simply place the iPad in another compartment.
2. As for battery bloating, the possible symptom include getting a quishy feeling instead of hard feeling when touching the iPad and even screen delamination. The touchscreen should still be responsive as per usual barring other issues like the one mentioned about.
3. Screen discoloration can be caused by either issue. This means you can use this as a visual indicator of sorts on the health of the touchscreen.
4. The Apple diagnostics do not have swipe tests unlike for the iPhone