This news follows a line spotted in Valve's latest SteamOS release notes: "Added support for extra ROG Ally keys."

Initially, it was unclear whether Valve supported these keys in the Steam desktop client on Windows or if it was a broader initiative.

However, Yang clarified that this is about Valve eventually supporting the ROG Ally and other rival handhelds.

"The note about ROG Ally keys is related to third-party device support for SteamOS. The team continues to work on adding support for additional handhelds on SteamOS," Yang said.

This does not mean that Asus will officially endorse Valve's installer or sell the Ally with SteamOS.

Asus has cited several reasons for shipping with Windows, including Microsoft's dedicated validation teams that ensure compatibility across various hardware configurations and chips.

Valve is making steady progress, but Yang noted that SteamOS for rival handhelds "isn't ready to run out of the box yet."

Valve has announced plans for a general release of SteamOS 3 that can be installed on non-handheld PCs, although it is not quite ready yet.

 Regarding dual-booting Windows on Steam Decks, Yang mentioned, "As for Windows, we're preparing to make the remaining Windows drivers for Steam Deck OLED available (you might have seen that we are prepping firmware for the Bluetooth driver). There's no update on the timing for dual boot support -- it's still a priority, but we haven't been able to get to it just yet."

This development marks a significant step for Valve as it continues to expand SteamOS' compatibility and functionality across various gaming devices.