Is the maximum size of the SD card for the S9+ really limited to 400 GB? Note: while this is not an exact duplicate, this question is a duplicate in that it asks where the limitation is located (software/hardware ...). So I think marking this as a duplicate is warranted, even though my question was model-specific.

I have an S9+ from Samsung and I am considering to upgrade to 512 GB or even 1 TB as it would make space for Kiwix ZIM files.

However, Samsung marketing material suggests a limit of 400 GB (i.e. 400x1000x1000x1000 Byte). This sounds arbitrary (not the usual power of two and the discrepancy between GiB and GB which may be accounted for by reserved space - in case of corruption - doesn't change that). Now, perhaps there is a technical reason that I am unaware of, but from the OS side (Linux/Android) I can't understand why there would be a limitation to 400 GB. SDXC seems to be the supported standard and should support up to 2 TiB (i.e. 2x1024x1024x1024x1024 Byte).

Is this limit simply owed to what was available around the release of the S9+ or is it an artificial limitation imposed by Samsung customizations to Android, or is there perhaps no limitation?
I can now confirm that the S9+ supports a 1 TB μSD card just fine.
After a colleague had outfitted his phone with a 512 GB card, I decided to give it a try, because it was already above the limit Samsung claimed was supported but well below the limit one should expect for SDXC (see my question).

Edit (February 2021): Due to the other answer which appeared here, I wanted to update the screenshot and also wanted to state which model I use: Sandisk Extreme (not Extreme Pro, though).
Also note: I have meanwhile read in several places that phone manufacturers indeed specify the &quot;supported card size&quot; based on the SD cards available at time of the release of a phone model.