This would be a dream a few years ago. I remember setting up a GargoyleFW[1] (a custom firmware based in OpenWRT) when I lived in a shared house and people would use the Wi-Fi to streaming/torrent and make the whole Internet sucks for everyone else. Setting up a few smart QoS rules made the internet feel fast even when someone was using most of the bandwidth, the average latency in those situations decreased from 2s+ to around ~50ms.
The issue at the time was this router was really low-end and had only 4MB of Flash/32MB of RAM, so using vanilla OpenWRT needed lots of customization and even (I think it was a TP-Link TL-WR841, but not sure). I always though how nice would be to have a proper device with lots of Flash and memory so I could play without being constrained by the device limitations.