@SusieQQQ
Thanks so much for a very detailed answer. I didn't know Britsimon was frequenting this forum.
He didn't say it was too late to submit the form in September, but that it was for some reason better to do it as early as possible? Maybe I misunderstood, because he was responding to a particular person. Given our circumstances (getting married, etc.), I take it that it's still fine to submit the form in September? Also, we actually prefer to schedule thw interview as late as possible, so I take it that it's fine from that angle as well.