Yes, max and min length for text entry only work in forms.
You could count the length of the text entry using a “text lengh” column.
Then on your button action, you set this logic:
IF, the data entered by user > than your limit of character THEN show notifications “max characters X”.
Then to know if at has already been use, you can create a relation between the data submitted in the text entry by the user and you column where all the previous submitted data is stored. If the relation is empty then the user can submit, otherwise he needs to change.