New to formula - 10.5 months

This is probably going to be long and a bit of a ramble but bare with me.

I am returning to work sooner than I had originally anticipated and needed to wean my LO off the breast for his 2 day feeds. He was nursing 4 times a day plus 3 solid meals. His 2 daytime nursing sessions were usually short due to solid intake. I have started him on 6oz of formula twice a day and am continuing to nurse morning and before bed. He has since lowered his solid consumption pretty significantly.

I guess my question is should I be concerned about the solid intake since the formula seems to have affected it? He’s only going to be on the formula for 1.5 months until he’s 1 year and then will transition to whole milk. Is 2 bottles during the day the right amount for his age if he’s nursing in the am and before bed? I spoke with his doctor about it the other day but got mixed messages - he said he should learn that if he’s hungry he eats solids but also said to offer the bottle on demand? On demand made sense when he wasn’t eating solids but he gets the bottle (prev nursing) after his naps as more of a routine than “demand”. Any help/guidance is appreciated.