Devices tested: Pixel 5, Pixel 6 Pro
DAC Model: Samsung USB-C dongle/adapter, US version
The WW version as mentioned above is underpowered and may have volume issues similar to the Apple dongle. The US version of the Samsung dongle does not have this issue. Sound quality-wise it's a very good alternative to the Apple dongle.
The model number on the back of the box will have either "WW" or "US" at the end of it indicating which one you have. If buying on Amazon, look at the pictures of the product and find one that shows the back of the box. You can make out the two letters at the end of the model number to determine which one is being sold.
Devices tested: Pixel 5, Pixel 6 Pro
DAC model: Apple dongle US version
As all Apple dongles, they sound amazing. And while the EU version is more underpowered, the US version is still underpowered (Android issue) and has low volume issues. Some might enjoy low volume, but it works none the less.
It's totally tolerable volume-wise and sounds great none the less.
Devices tested: Pixel 5, Pixel 6 Pro
DAC Model: FiiO BTR5 2021
Tested both USB-C and Bluetooth and all works great. Even supports simultaneous Bluetooth connections to more than one device and no issues there. I don't recommend the FiiO app in general, it's very invasive in permissions (all files and media, location access) and feels too janky. It does offer some edge-case tweaking functionality like more control over the filters, EQ (you can just use Poweramp for that), etc but overall it's not important and the device itself has some physical controls for these. Sounds great, like all FiiO products :)
Devices tested: Pixel 5, Pixel 6 Pro
DAC Model: VE Odyssey HD
Despite reviews online and for some reason praised, it's not great sound-wise. I've tried three different IEMs, open back headphones, semi-open/closed headphones, even trying this on my computer and other unrelated devices and everything just does not sound good with it. Very little soundstage, all the music sounds mushed together like if you bought a cheap random USB-C DAC from Amazon for 5 dollars, sounds worse as you increase the volume. There is also a hissing noise with it when it's playing audio. The chipset is a Realtek ALC4042 SoC and I don't have very good experience with Realtek and audio.
Does it work with GrapheneOS? Yeah. Is it good? No.