It's ok to start working on the essays early. If you are expecting some major developments in the coming months, there be might quite a bit of re-work needed, or the essays may start appearing stale...like that Sharman Joshi movie that got shot 9 years back, but just got released to cash in on his newfound fame. Well, off-topic, but you get the point.
Also, if you are concerned about what Adcoms might think (I don't think it's an issue though), you could just work on a MS Word doc and keep it on your laptop.
The most time-consuming aspect of bschool apps are the essays. The rest of the objective data is relatively easier to fill in.
So why upload it 3-4 months in advance on a third-party website, when it's easier to access, update and backup the same content on a PC?
But just curious. If you are starting now and you have all the inputs ready, why not aim for Round 1?
Sameer Kamat | Founder - MBA Crystal Ball | Email: info at mbacrystalball dot com