That is one of my biggest fears with regards to bottle feeding (even pumped bm in bottles) - rejection of boob.
If I ever have another kid, I would hope to be able to share the night feeding duties with my partner, but I'm not sure I'll be able to, given how common it is for breast + bottle-fed babies to start rejecting the breast in favour of the bottle.
Because L ended up developing a nipple preference (for bottle nipples) I am definitely worried about what will happen with a second baby. I read a lot (too late) about how to avoid the preference and in retrospect I see I made a lot of mistakes, although I was doing my best in the circumstances we had.
I was separated from L during the day from 12 weeks onwards which I'm sure also affected things. It seemed like too much to ask L's caregivers and my bf to feed him with a slow flow bottle and not let him suck it all back at once, there is a technique to bottle feeding a nursing baby that helps to prevent a preference from developing, which is basically to make bottle feeding less convenient and interrupt it the same way that babies have to take breaks when they're nursing. I'm definitely doing that next time, but L's caregivers would complain it took him forever to drink a bottle and that he would pull off a lot and so I was actually happy when he started adjusting to the bottle with a faster flow, doi.
He started rejecting me in the daytime after I went away for an overnight conference, I came back and it was like he had learned that bottles are great, and formula is tasty. I started supplementing because I got tired of rushing home every day to feed L but that reduced the amount L nursed in the evening and it snowballed from there. He would also go on strikes if he was teething or sick and I gave in and gave him a bottle and I think once I was feeding him bottles he dissociated my boobs with food.
I fought it by trying to pump my supply back up and offer as much as possible but it was seriously demoralizing to offer the breast and have L just bite me (and he had several teeth at that point too), he was done, although he would still nurse at night when he was asleep once or twice but that meant never getting a break at night. I saw an LC who told me to pump about 1.5-2 hours a day to get my supply back and it was just too much with a crawling baby and fulltime school, although I tried for a couple of weeks, and I nearly got a domperidone script, but my bf thought I was nuts, and no one seemed to care but me so I let it go, although I was really angry about the whole deal at the time. I also felt really guilty because I had had a great supply, L had no problems nursing, it was lifestyle choices that created the issue. That said I was unable to find many stories of moms who had had this happen and saved the nursing relationship, and I wonder if all of my fighting it was worth the stress when I could have been enjoying my time with L.
Oh and MM I commend you for making combo feeding work. I think pumping, nursing, and formula feeding altogether is so tough, especially when you're not away in an office pumping, I could barely handle that even. I'm hoping to have a job that allows me to take a full maternity leave with the next LO and then these things won't be such an issue for me hopefully.