Well, it can be argued both ways -- yes, it will be nice if the Write Tag VI warns that the string length has exceeded the specified limt -- no we don't need a warning since you have explicitly specified the string length (and thus implicitly agreed that the rest will be truncated).
Anyways, if a warning is desired, a workaround would be to check the length of the string (using the string length function) before writing to the Write Tag VI and then flag some kind of error.
Hope this helps.
Regards,
Khalid 🙂