I know its been talked about to death, but its really worth considering how flawed the HCMT door buttons are for tourists in general
Most metro system doors would have a tactile button that can be pressed with movement, or in the case of the Comeng a door handle. Yet, the HCMT has its weird button that feels like pressing a flat surface button, with no real indicator of how much pressure is needed to activate it.
Keyword here is a pressure indicator. I was boarding a train on West Footscray with a grandma and her grandson trying to open the door. They did not realise how much force was needed, so were obviously confused when it did not open. I pressed it for them and explained afterwards, but it really is such a terrible feature in an otherwise good train.
Tl;dr hopefully the X-Trap 2.0s and future trams and trains just stick to conventional buttons