With episodes 5 and 6, I get the feeling you could very easily cut out most of the Hera and Jacen subplot, as well as the New Republic arriving on Seatos, and instead intercut Ahsoka’s WBW journey with Sabine and the others on Peridea? That way, once Ahsoka rides the whales, the witches alert Thrawn about it. I think it could make it a lot tighter, and we could reduce the Jacen subplot to an expository line. I also feel you could cut out the New Republic arriving, and have Ahsoka depart with no interruption. If they are still on Seatos and that becomes a plot point, you could easily slot in their arrival after Ahsoka leaves.
I would only caution that I think Jacen is going to be a very important character eventually, given that he is very Force sensitive. Might be a mistake in retrospect to cut down his story too much. I also liked the part where he could hear Ahsoka and Anakin’s lightsabers clashing (although I didn’t understand why tf Hera could hear it, too).