I work for a news agency that restricts character counts in the Description / Caption / Headline field in IPTC.
It would be super useful if you could as part of the setting for FTP indicate the maximum characters for each field, and then have an indication of how close to the maximum you are whilst typing in the stationary pad, only if a maximum has been added in the FTP settings.
It could be something as simple as a coloured square that highlights the last letter which will be sent, so you could continue typing with extra detail but know that it will not appear on the agency.