In the example of two 0.0015 deposits, both are above the minimum chip size. In your example, the second deposit is below the minimum chip size and is therefore treated as a donation.
Understood, but the final statement asserting merging seems to overwrite the previous statements, or that is a general reading in english.
If that is indeed the design, the wording chosen is not appropriate.
Or at least that's my take.
you misunderstood the example in the faq,
the minimum amount per deposit (1mbtc) is still intact
the minimum amount rule applies to each deposit (utxo), NOT total amount of deposit
that statement gives an example condition of 2 deposits over 1mbtc each
the example simply explains that you won't lose the fraction if they sum up to a full mbtc