Benefit to submitting D-Plan early?

Hey all,

My sister just started at Dartmouth and absolutely loves it. She’s pretty much set on a major and thinks she’s ready to submit her D-Plan for approval (even though it’s only her first term). Can anyone with experience tell me if there is a benefit to submitting her D-Plan early? Is it more likely to be approved, will they get back to her sooner, etc?

I’d also like to know if there are any drawbacks to submitting it so early?

Thanks!