Warren - do you plan to upgrade your book because I will place an order now please 8)
This is the perennial problem with 'books' that are printed to support fast-changing, constantly developing field such as PixInsight - they will 'neve' be up to date. In fact, as soon as they are 'put to print' they are almost immediately 'obsolete' (at least, in part).
Now - that isn't the fault of the author - other than their choice to publish information on whatever field is the subject matter of their book. Further, remember that these books are published, first and foremost, as a 'commercial product' for which the author hopes to gain sufficient financial returns to at least cover their production costs, if not to afford them an income from the project as well.
So, when a book has to be 'revised and republished' a whole new set of expenses are incurred, which must now be borne by a market where those who have already purchased an earlier version will not consider purchasing the new version as well.
Personally, I used to spend a
lot of money on reference books and manuals for the many and various fields that I was interested in, but have (for quite some time now) decided that this is just not financially viable any more - not with the wealth of information already available - for free - on the internet. (Just in astronomy and astroimaging alone, I have a stack of books over 5 feet (1.5m) high, and my Software Development manuals would be closer to 8 feet (2.5m) high - enough to reach the roof!!!).
Perhaps Warren might publish an on-line addenedum to his physical book (I am not suggesting that he should - it will have to be his choice). Perhaps PixInsight users will read that (for free) and decide to actually invest in the 'missing' information. Who knows.
In the meantime, I do expect that there will be a reasonably detailed write-up made available here, on the PixInsight Forum, by those who were intimately involved in creating the new developments. And, no doubt, there will be Video Tutorials that get created as all of us start to learn how some of the new ttols work.
Hope this helps (and I hope that Warren is already bashing away at his word-processor!!!)