The issue is that if you exceed the (invisible) limit, you start overwriting the existing data. That's Bad (TM), since there's no indication that it's happening, until you attempt to retrieve the data and discover it's corrupted.
The subject of this topic, f3, will quickly probe the drive, determine the true size, and create a partition on it of the actual usable size. Using that partition, you will never lose any data. If you try to create a partition in the rest of the drive, it will be immediately corrupted, no tools will show it as good, you won't ever be able to get around to putting data on it to lose it.
Some scam SSDs are smaller drives with hacked controller firmware that is bright enough to avoid detection with quick scans - you have to write beyond the real capacity then re-read to confirm corruption.
> Using that partition, you will never lose any data.
... unless/until the underlying flash fails. Which it probably will; there's every reason to expect these drives are made with the cheapest, worst flash available.
