Do Anyone use the Growing up milk( not Follow On milk) for their 13 months old baby as a regular milk drink?

My baby is 13 months old.She drinks cow and gate from her birth.First stage 1,then stage3 and now she is on stage 4.Stage 4 says i can continue with it upto 24 months.But at the same time i saw cow & Gate Growing up milk is sold in the shops for babies 1-3 yrs.I already started buying them.But they r too costly.But they r tasty.My baby likes that.I am not worried abt the cost.I just want to know,whether people use growing up milk bottles for travel purpose(bcz they r ready to eat) or daily for babies usual milk? Normally people shift to COWS MILK when their baby is 1 yr.But i want to continue with formula upto my baby is 18 months.The problem of growing up milk is they r sold ready to eat form just like other ready to use milk.They dont have any packet of powder milk.People who wants to advice me on cows milk,or as i am not worried abt the cost so i can continue should not answer this question.I am expecting answers from those mums who use growing up milk as babies usual daily milk