edit -- First of all, thank you for giving it a spin!

The reasoning to have the form available is that I think you should be able to change your goal as you please.

It could be hidden though and only shown when you opt out of the current one.

For my own experience, I've been using it for about 10 days (usually change goals once or twice a day) and it has been working out for myself.

I would definitely like to hear your progress: Is it just a nice idea or something that actually helps.