You're quite welcome. To be perfectly honest, your reaction to Outlook conversation view is far from the only one that I've seen expressing the same sentiments. Every time I see it my first desire is to reach out and throttle the person making it.
Outlook is an incredibly mature product, and probably is the best-supported by screen readers in general. Most of the time issues are not with Outlook, but with ignorance about how to use it (whether that's getting it to do something you want it to do or stop doing something you don't want it to do). I didn't even know about the CTRL+Arrow keys and discovered it in response to the questions raised here. I generally figure that, when it comes to Windows based programs of the age and stature that Outlook has achieved, that there's almost always some keystroke sequence to do virtually anything whether I happen to know what it is or not. I experimented to find this one, and I also experimented to discover the two-level expansion. I found that the latter is well documented after having discovered it myself.
I get, more than you might think, the kind of frustration you had expressed. But what my years "in the biz" have taught me is that there's generally a solution I don't know about when it seems obvious that a lot of people other than myself would probably be screaming if there weren't.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
A great deal of intelligence can be invested in ignorance when the need for illusion is deep.
~ Saul Bellow, To Jerusalem and Back