yes - this is an effective way of managing. All they need proof of is ‘onward travel’. Not only return tickets. Not only airlines tickets. Just onward travel as you provided
it’s not always the case, but seems to depend on location of origin and the airline. I was denied leaving LAX last year by Qatar airways, and several people on same flight. Had to buy on the spot.
It’s wise to do as you are and at least be prepared with proof of onward travel just in case.
I only fly one way tickets, but sometimes you run into a problem. It’s rare though