unfortunately) if the Super Card configuration is "ShortName": "keycard_red", then when using a Super Card on a red cardreader, it will open, and everything is fine, but if you use a Super Card on a blue or green reader (green, for example, in some other event), then this cardreader is buggy and it won't even be possible to open it with the default card anymore, I've already discussed this with the developer, and he said that the Super Card developer should fix it, which is sad news for me too, because I also use the Super Card..
But I need to clarify that I noticed this behavior only on cardreaders in events, on standard monuments (cardreaders) it's working properly.