We were perfectly comfortable with safeties that were not 100% published data safe. But that’s because my kids took advantage of EA, priority applications and/or rolling admissions. Each had one acceptance in November - the best kind of safety of all.
Many schools don’t look at majors for prospective students. Harvard explicitly says it doesn’t, however I suspect the fact that they were expanding their engineering and comp sci offerings the year my oldest applied as a very obvious computer nerd was probably in his favor. But you know if the difference meant he had a 12% chance rather than a 6% chance, it’s still a reach.