We get this question a lot, and the answer is usually no. There are a number of complications:
- the QR agent might say yes or might say no, you'd have a wasted trip to T4
- what happens if your BRU positioning flight doesn't work out as planned and you don't make the return, what if the return is late or cancelled? In these cases your QR ticket would be cancelled. How much time have you built in at each point?
- have you considered left luggage instead?