I would argue that’s actually the last situation you’d want to use an LLM. With numbers like that, nobody’s going to review each and every letter with the attention things generated by an untrustworthy agent ought to get. This sounds to me like it calls for a template. Actually, it would be pretty disturbing to hear that letters like that aren’t being generated using a template and based on changes in the system.
The biggest issue with the three-pedalled bicycle is that humans have, at most, two legs.