I recently connected both outlets into one, I got fed up with trying to stuff two pipes into one container.
The problem I had was getting hold of the plastic fittings. The o/d of the pipe is 28mm which is the same as copper pipe (or very similar) so I ended up using one copper tee.
The good thing I discovered was that the existing pipework is only push fit with no sealant so it made the job a lot easier.