its designed to allow being over writen incase your on the last seconds, also, if they add another type of seal later on, it will overwrite/be overwriten much like dedication and comitment,

If don't have time to reapply (Due to fighting or something or stuned or paralyze, etc etc) or you didn't notice at all, if you remove the overwrite function, you remove it for those that need atleast something since it probably will wear off at a critical moment. Your mistake is your mistake, its the same thing if you had clicked "Drop" instead of "Use" , its your own fault, noone elses