That's a great idea StephC....but unfortunately there is no way the VO will become aware of your presence. Rest assured that, if they want or need more documents, they'll ask, and your plane tickets will act as the same thing.
Now here is a suggestion to all....Stay away from embassy....in fact stay away from all correspondence unless required to because of a change in circumstance and/or unless contacted by them first....(eg. Interview request). Further to that suggestion, lets say they do send principal applicant interview request.......now here is your chance.
My plan is, if they do ask my wife for anything we send them promptly, and that's it....BUT, if they ask for interview, then I'll send email to embassy contact email as provided by my sponsorship approval, stating that I'll be visiting my wife at that time and would love to attend the interview with her if possible......as an example, I believe this is the best type of correspondence method
Cheers!