I slowly mixed formula and cows milk from about 11m with my little girl. Gradually became more milk that formula then was just milk at 1. She never seemed to notice.
Might be as his milk is sweeter ill give it a go half and half tomorrow thank u then if not ill do the other option
My oldest refused cows milk and the dietitian said that soya was okay so he had that until he stopped wanting bottles at 2. We used the alpro growing up soya milk. Original advice was for children under 2 to have full fat milk but apparently that's recently changed.