I don't care about frequency - I have female cousins with deeper voices than me. So as long as I manage to change my timbre and so on over time, my pitch is fine. I would only go for VFS if changing those things proved overly difficult; while VFS won't solve such problems, it could at least make them less noticeable.
Thankfully my voice has changed quite a lot over the last few months, partly due to less anxiety and dysphoria, partly to training, and I also suspect some muscular changes or something making it easier to use the voice differently. But this could also of course be my (although very limited) training having effects. Either way, since people seem to gender me a bit randomly on the phone now, I'm hopeful that I can have a passing voice within a few years, without surgery.