Well its either or. Some people like placing their beardies crickets in a different enclosure so that later on they don't have to take out the crickets. If you decide to put your crickets in your beardies viv then you need to make sure that after he/she's eaten to he's/she's fill that you take out all the extras because the crickets will nipple on your beardie when he/she sleeps. But if you put your beardie in a cricket enclouser then all you have to worry about is taking out your beardie and putting him back in HIS/HER cage instead of having to chase down uneaten crickets.
So it's really all up to you, whatever you feel better doing.