Does this have an SD card slot? – Q&A – Best Buy - bestbuy.com
iVANKY 14-in-1 RGB 4K@120Hz Docking Station for Steam Deck OLED/ROG Ally X/Lenovo Legion Go, Foldable Dock with HDMI Gigabit Ethernet 10Gbps USB 3.2, SD/TF Slots, 1Gbps Ethernet, 100W USB-C Charge : Amazon.ca: Electronics.
How to Fix the "Steam Deck Unable to Format SD Card" Issue?
Locate the SD card slot on the Steam Deck: It is usually located on the right side of the bottom of the device.
ROG Ally SD card not reading! - Republic of Gamers Forum - 939021
The only major flaw the ROG Ally has beyond the battery-life tradeoff vs the Steam Deck OLED is it's QA issues with the SD card Slot.