Well, starvation mode is largely a myth. examine.com/faq/how-do-i-stay-out-of-starv
However, there are some negative consequences to what you're doing. Too large of a calorie deficit will result in fat and muscle being burn indiscriminately as the body looks for ways to fuel your deficit. SP via the nutrition tracker is attempting to help you avoid this because building muscle is a hard, slow process. So preservation of muscle is important.
I say go with SP recommendations and lose the fear through education.