I have a bag of both as I personally do not like m-chaff it is just so dry and yuk so he gets chaff in the morning and alpha in the evening.
He is used to getting a bucket of chaff for breakfast from his last home and gets a bit put out if he doesn't get it difference is now he has meal with it and alpha with his meal in the evenings and haylage to munch during the day.
I have getting him a mineral tubby instead of his usual lick to see if that helps as well, I now have to put his buckets in the wheel barrow at meal times as they are too heavy to carry all the way to the field, my friend laughed and said would it not be easier to just mix it all together and feed him from the barrow
i know where she is coming from when you see the amount he has to have at the moment.