Disappointed with The Navigator's Children

Is it just me, or does anyone else feel The Navigator's Children wasn't a satisfying conclusion? Am I missing something, because when I think about it, the reveal of >!Geloe being the one revived instead of Ommu and then calling the Vao to the Witchwood Crown doesn't make sense. Why didn't she do this centuries earlier? The ship has been in Osten Ard for over 500 years. Was it only in death she had the power to call them? Not to mention I feel like the spirit of the Witchwood Crown would have been a nice weapon to have during the Storm King's War. I know the answer is that Tad hadn't thought of the Witchwood Crown when he was writing MST, but I feel like it introduces a bunch of logical and plot inconsistencies now.!<

Also, I feel like Unver and Pasavellas don't act like they did during the first three novels of TLKoOA. Their whole subplot kinda just sputtered out.

I loved MST and the first three novels of TLKoOA but I feel like Tad didn't know how to wrap up the plotlines he set up (not to mention some of them not being wrapped up whatsoever). I know there might be future novels, but I feel like introducing plotlines in a series that don't have at least some resolution within the series they are introduced in is a letdown.