Milk ladder final step and thickener?

Hi everyone, We are currently on step 3 of the milk ladder and after 15 months of every intolerance under the sun, we are finally (cautiously) optimistic and thinking ahead for the last few steps. She is currently on SMA Alfamino and carobel thickener (due to having allergies to soya, coconut, oat specifically but gluten in general meaning the only milk alternative available was almond milk and the dietitian advised against that as it has no nutritional value compared to her formula) and my question is has anyone made it to the final step and had cows milk mixed with formula had to add thickener? Or should we be trying to stop the thickener before we get there? She still takes lansoprazole every day and has two bottles (morning and night) but I don’t know if it’s better to try to move to cows milk and then cut down on carobel once we’ve switched to cows milk fully or the other way around? Any advice or your own experiences would be great because the dietitian is great but hard to get hold of 😭