Molgrips. Avoiding the bonk is to do with keeping your energy stores at the correct levels and making sure they do not get reduced to such a low level that you have passed the point of no return (whereby it’s too late and any food you eat will not be turned into the necessary volume of energy you need).
Therefore, whilst you are correct that liquid food is digested quickier thank solid, all that means is that you have to eat your choice of food at the correct time to ensure it has the time/process involved to be converted to the energy you need.
Therefore, avoiding the bonk is about the timing of your food intake and ensuring your stores do not get too low (which is why you should eat before you get hungry).