No matter whether Angel's guess is correct or not, it is indeed a reasonable line of thought.
However, they currently have not followed this line of thought to inspect various parts of the ruins. After all, this ruin isn't too big nor too small, and wanting to inspect every place one by one to find clues to the "bedroom" will certainly take much more time than simply looking for anomalies.
It should be noted that even Tizarro only modified the copper plaque on the door two hundred years later, which means he didn't discover anything in the first two hundred years. Even Tizarro took two hundred years, so they might not be able to find it quickly.
Additionally, they are not sure whether the anomaly of the copper plaque is related to the hidden room. If it is just for the title of "bedroom" and they expend energy, it's likely to be a futile effort.
