I look forward to when people just intuitively understand that on these units, “single hose” means “Do Not Buy.”
Why do manufacturers continue to do this, when doing it right is so simple and cheap? That condenser intake vent on the back of the unit – just make that into another circular port, and add another hose to the bill of materials. Put another round hole in the window bracket to connect it to. That’s it. Choosing not to do this means selling the customer a monumentally inefficient air conditioner, that’s literally fighting against itself by sucking hot air into your home.