Well of course if you don't want to breastfeed that is your decision. And whilst there are high breastfeeding initiation rates in UK, that proportion quickly tails off, so you won't be the odd one out and in most circles your decision won't be unusual. And you definitely have body autonomy to decide what to do with your body.
However do make sure you are making the decision for what you think is best for yourself and baby. Two of the three reasons you mention are re your partner, not yourself or baby. Of course dads are vvv important but having dad involved doesn't need to mean separating baby and mum in the early newborn period. Not to be unnecessarily mushy, but there is a special biological and emotional relationship between baby and mum in that period when her body continues to fully nourish baby, and baby's heart rate and breathing slow when close to her and smelling her, and I think often the most important thing dad can do is to support this relationship in the early weeks. There are plenty of opportunities for dad to take centre stage later on.
There are also many opportunities for dads to be involved apart from feeding, eg nappies, winding, bath, dressing, sleeping. Dad can take baby out if baby is mix fed or mum expresses, or for short periods timed between feeds, or as long as they want after baby starts solids around six months. And I was surprised when I had my eldest that I didn't want to be separated for the first several months (not what I'd planned at all!), the strength of that attachment surprised me, so my DH just took baby out for an hour in between feed.
Also in reality I often speak to mums who decide to formula feed for dad's benefit and to "share the work", and once dad is back to work after 2 weeks it's mum up at 3am making a bottle every night. If it goes well then breastfeeding is extremely easy, no prep, no equipment, no planning, can breastfeed half asleep, lying down, walking with a sling. If you will be doing the majority of baby care on maternity leave do think about what will suit you and baby best.
Anyway apologies if I've misunderstood your reasoning, but from your earlier post 2/3 reasons were about your DH, not you or baby.
Re your breasts - women of all shapes and sizes can breastfeed with support and help. A lactation consultant/ infant feeding coordinator can help with positioning, there should be one on your postnatal ward.
Anyway your original question, of course yanbu to make your own decision, but in honesty i wouldn't advocate making definite decisions early in pregnancy. There's something to be said for seeing how you feel after baby is born and how things go. I cared for my babies in quite different ways to how I planned during my first pregnancy, you change during pregnancy and labour, your baby has there own personality, things aren't always as you expect.