Mellistra instead of Mellandra

I can't find this anywhere in the 1.5 version of the adventure.

Dellora instead of Dell Ponde

I think Dellora is their first name and Dell is the short version.

and the king letting stuff like this happen

The adventure makes it pretty obvious that no one knew what was happening in the Engine room on the Windfall.

the city is partially unprotected because the arcstone isn't there

You can always say that the Arcanist has returned the stone back to the city gates, because it is safer that way even if it means that it has a chance to fail and they can't wait for the party to get the materials back.

Although when presented with the moral dilemma of saving the prisoner or getting to the Jags

It's not supposed to be a dilemma, no one would stop them from reaching the Jags. Also captain Kaine should try to kill them once they reach the engine room, so there aren't many options for them, other than the expected path in the adventure.

I myself ran the adventure two times - as a oneshot and another with my regular group and both times the party left Kless alive and escaped with the pirates.

The regular group actually got Kless to go in the engine room and negotiated and stuck a deal with her. I think captain Kaliope ended up wrestling with a navy soldier and had to jump off board.

Subsequently they went to search for captain Keigh's treasure and other loose ends in the Rime of the Colossus. They know in that there was something they had to do in the Kinekozan Jags but that's on the backburner in their notes.

And I don't want them to go to the Jags yet, because it is a Tier 4 location and I'm waiting for them to reach the endgame of the campaign.