I just bought the new Google TV Streamer 4K to replace my NVIDIA Shield TV Pro. I've been using Flirc with my Shield with no problems, and had assumed it'd be a simple swap to the Google box.
It wasn't quite as simple as I thought. The problem is that the Google box only has 1 USB-C port on the back, for power. There's nowhere to plug in an additional USB device. I hoped that I could solve the issue with a USB splitter, so I hit Amazon and found an adapter cable that looked promising:
"USB C to USB Adapter with Type C Charging, 2 in 1 Type C 3.0 OTG Splitter with 60W PD Fast Charge Compatible with iPhone 15 Pro Max, Galaxy S23 S22 S21,Switch,LG V40 V30 G8, Pixel4 XL,Google TV 2020"
https://www.amazon.com/gp/product/B098SVSDYW
I can confirm this works! Once I got everything hooked up, my remote (already set up for Shield) "just works" with the Google box, as expected.
BTW, so far I find the Google TV Streamer 4K to be a nice upgrade from the Shield. The interface seems a little smoother, it runs a newer version of Android, and it also doubles as a Matter-enabled smart home hub.