Yeah, you are probably right, but since this is like my nineth time trying to contact the devs over the last year, which have all remained unanswered, I'll risk displeasing the staff members, if I can bring some attention to this matter.
Still thank you though, I haven't thought about it that way.
This is normal behaviour since you've set your screen area to only a single monitor in your tablet software. Set your screen area to be all monitors in your tablet software if you want to use 'map absolute raw input' with multiple monitors.
I wasn't exactly suggesting a solution but rather explaining the behvaiour (and also have also dealt with this before). I strongly doubt this can be 'fixed' as a mismatch of settings both inside and outside of osu!, hence what I said in my previous post. It works perfectly fine if you set it up as in the following screenshot.
No worries. I wasn't being very detailed with my initial post either.
To answer your question though, well, yes. It's not intended behavior, but it mechanically (/ logically) makes sense why this happens.
To further elaborate, both osu! and your tablet software function in essentially the same way when it comes to scaling monitor and tablet area. osu!'s sensitivity scaler is essentially the tablet area in your tablet software and the 'map absolute raw input' is the screen area. Either one has to be set to its default settings as they both add on to each other, which is why the behavior is what it currently is. If you didn't have your tablet software installed (so that the settings aren't running) or had a tablet without software in which you can change these settings it would (and does) work as intended, which is essentially the setup showed in my screenshot, except that the tablet area is downscaled.
With that said, I don't exactly think the devs can make osu! can't ignore/undo your custom screen and tablet area from your tablet software, which is why I said it strongly doubt this can be fixed (/ worked around).
Oh, and the second cursor on your other monitor (unfocusing osu! when clicking) is another quirk with this. While osu! can scale the sensitivity of its own cursor, it can't change that of the windows cursor, the best it can do is lock it inside its area.
All in all I don't really see how this could be improved (without magic, lol), feel free to suggest things though (and correct me if I'm wrong on anything I said).