At many schools, legacy is of significantly more value if it has come with significant donations to the school. For a handful, meaningful engagement by the parents may also matter (i.e., advisory board, reunion organizers, etc.) Your parent’s degree and history of four-figure gifts will likely not move the needle. My point here is that you may be overestimating legacy’s value to your application. Fwiw, a friend’s kid was turned down by the HYP where both parents had graduated. That same kid is finishing up a degree at another HYP where there was no family history. Iow, qualified applicant, legacy didn’t help.
If that “privileged special situation” pertains to you AND you are fundamentally qualified, your legacy simply moves you to the front of a line filled with other equally qualified applicants. Just like being the much-needed bassoon player would. Or the exceptional runner. No need to feel that you are an imposter for this. You’re just lucky for your lineage.
Otoh, if you are a mouth-breathing dud whose lips get tired when reading and whose parents have given so very much that the school feels obligated to admit you, you and your classmates will probably recognize that you don’t belong there and will also recognize your legacy status as your surname will be on a notable building. That might not be great. Only you know where you fall in all of this.