Unfortunately, when I did write a book using many smaller documents in Scrivenings view, I constantly had to deal with this Windows-only bug, which I found really disruptive.
Also, if I’ve structured a project like that, I want to be in Scrivenings view 100% of the time, but pretty frequently I would find that because of something else I’d done, Scrivener had reverted to showing me single-document view. Of course, at that point I can just click in the binder to return to Scrivenings view (then wait for it to load, then navigate back to wherever I was…) and no doubt others would dismiss this as a “minor inconvenience”, but to me it’s a completely unnecessary bit of friction when I’m in the flow of writing. (Unless perhaps there’s some technical solution to this that I don’t know about?)
After some further testing, I’m finding that splitting the 100,000 edited manuscript into three documents reduces, but does not eliminate, the lag when browsing comments.