The sixth Majo to Youhei volume is split into two books, a bizarre practice some authors insist on despite how pointless and annoying it is to muck up the numbering that way. That issue aside both halves are perfectly fine and provide a bit more information about witches and why they tend to behave as they do.
I bought the second Isekai Goumon-hime novel way back after finishing the first and just… never got around to reading it. While I would not say the series is bad, there’s just something off about it. A general sense of incredulity that makes it difficult to form an attachment to the characters or events.