i gave the carnation ago in my weekday naan.
1st go i used 1/2 milk 1/2 carnation (SR flour 450g, salt 1/2 tsp, carnation 50ml, milk 50ml, water 200 ml).
i did not feel it made a significant difference.
on 2nd go i used carnation instead of milk ie 100ml. it worked well and turned the naan into my posh version (when i use yogurt instead of the milk).
my conclusion is u can replace yogurt with carnation and achieve an equivalent result.
only point of caution is that carnation (and yogurt) does not have the same amount of free water as milk and i needed to add more water (60ml) to get the dough back to "UB's sticky" texture which i've adopted along with the "pat a cake" trick.
many thanks Andy. for me yog's hardly ever in the fridge where as there's always a tin of carnation so luck's going to be in from now on.
best wishes