SUMMARY Currently as I learned, there is a size limit for the trash. To my understanding that means that files from the trash get auto deleted if the limit is exceeded? If that is the case then that can lead to unexpected data loss. Thus I strongly suggest to have no size limit applied by default to prevent this unexpected behavior from happening. I might be wrong with the assumption that files get deleted from trash if the limit is exceeded. Please correct me if that is the case.
Although the default size limit for trash is 10%, the default action is "show a warning". In other words, under default settings, oldest or largest files will not be automatically deleted even if the trash is full. Reference: https://invent.kde.org/frameworks/kio/-/blob/master/src/ioslaves/trash/kcmtrash.cpp
You are right, thanks for checking. I should have checked myself before filing this :)