Thanks for the comments - we will see how it plays out.
viabtc offers to 'rectify' the situation for just ~0.09 BTC and I am not quite willing to pay for that.

I am using a coin-specific multiwallet that does not have much fee control- but this would have happened with any wallet I guess,
because the culprit is the incoming TX.

I guess electrum or bitcoin core would have displayed the pending dust TX, but that also can be overlooked.

What weird behaviour, I seem to remember that the dust attacks from 2 or 3 years ago were allegedly done as some kind of marketing gimmick.
 I just hope it gets dropped from the mempool sooner or later...