This felt worthy of an update, so here it is. Writing has gone much, much better in May. I'm not wildly ahead yet, but I'm no longer struggling to get anything written. Based on my current travel schedule, I'll lose a few writing days in early June, as well as the last week of June and the first week or two of July, but those aren't critical.
All of that means all signs are go for a late June start to publishing Book 7. Unless I do in fact get wildly ahead, posting will start at two chapters per week. I hope to get to three, but that will require a sustained period of making sure writing holds up. I have less traveling is the rest of this year than I've had up to now, which is a good sign.
Thank you for your patience! The early chapters of Book 7 turned out to be rougher than I'd expected, and having the time to fix them will make the entire book better, I think.