As I understand it an appointment has to be made at local office, biometrics, etc and then they take package and send it on to the NY office and then onto UK. The problem is that we have compiled documentation current to the present. If I wait, we will have to compile more docs and then pay the solicitor again to review and prep letter. I know its a faff. Should have waited I suppose but we just wanted a back up plan, like I said and are ( or maybe were...see my other post) excited to be together.
I just read your other post...wow. The people here are really good at coming up with the sort of suggestions and advice that you are looking for there. I'm more a bit of an old cynic of the mind that you might be best just to cut your losses and get out. Maybe though, if your wife gets her US visa and you set up as a family there, life will seem rosier, and you will get on a bit better? I'm not sure that I can see, with all that you have said, that it will work out for you, yourself or you as a couple living in the UK.
To get back to this topic though, if you do apply for your UK spouse visa, you are correct that by delaying the application, you would need to update the evidence that you submit because of the dates. Maybe though, you would not need to use the solicitor next time, after all, you will have all the template already, right? Also, most people choose to do it by themselves in the first place anyway so it is absolutely possible to have a successful outcome as long as you are very careful.
After you submit your online application you will then have the opportunity to book your biometrics appointment, you can take this in LA, but you will have to send it to the New York hub, they don't take it from you at the biometrics appointment.