Combination feeders…when to stop breastfeeding?

Hi all! Currently my 3 month old combination feeds and has since about two weeks old (she has a tongue dysfunction so is not able to get quite as much milk out as she would otherwise). We supplement about 8-10oz of formula over 4-5 feeds (2oz bottles). I find to breastfeed and bottle feed it takes almost 50 minutes of her wake time and worry she doesn’t have enough time to do tummy time and get development time in (her wake window is about 1hr 15min). I love the bond we have breastfeeding and that it can be comforting to her and to me, but during the day she also battles getting a full feed because she loves to look around and adventure. Any advice? Anyone who has done combo feeding, how long did you last before going to just formula, pumping or did you tough it out without having any detriment to kiddo for how longggg each feeding takes? Thank you so much!