TwinView Dock questions & suggestion

[BPM]

Please tell us some basic information before asking for help:
Model Name: ROG Phone 3 ASUS_I003D
Firmware Version: 17.0823.2012.131
Rooted or not: No
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So, I really like the TwinView Dock. Probably one of the reasons I got the ROG Phone 3 over any other "flagship" phone. There are a couple of questions I have about it, though.
I cannot seem to take a screenshot or record the second screen. Nothing I try (three-finger gesture, power button menu, or notification bar tools) seems to let me capture the second screen. I could've sworn the three-finger gesture worked before... but I could be wrong. Any suggestions?
I kinda don't like that plugging the phone into the TwinView Dock forces everything to be in landscape orientation. My main usage for the TwinView Dock is for running two different apps at once, so I'd like to have an option to keep everything in portrait orientation.
Any suggestions of a case that fits while using the TwinView Dock? I have a case right now, but it's a bit too thick to fit into the TwinView Dock (or the AeroActive Cooler, for that matter) Will the Lighting Armor fit? Or is the only option the Aero Case (which I'd rather not use, since the one that came with my phone covers the air vent...)?
Thanks!

[Gustav_ASUS]

@BPM
Go to Settings -> Advanced -> Screenshot -> Recent apps key -> Select 'Tap and hold to take screenshot' in the list. You need to disconnect the dock to change this setting.
To record the second screen, simply swipe down the quick settings menu on your phone when the dock is connected, tap the screen recorder and swipe away the quick settings menu. You should now have a notification on your screen asking you which display to record.
Landscape/portrait depends on the behavior of the app.
No, it won't fit with the Lighting Armor Case.

[BPM]

Thanks for the responses!
Unfortunately, that's not really an option for me, since I use the hold function on the Recents button for multi-window. Ideally, the other options to take a screenshot (three-finger down swipe, power button menu, etc) should be updated to work on the TwinView screen.
Okay, for some reason, that wasn't working before. It's working now, though.
Having the TwinView connected forces things like the Recents list, web browsers, messengers, Gmail, etc into landscape with no option to rotate to portrait. Ideally, there should be an option to allow for forced portrait or auto-rotate when the TwinView, that way we can pick what works best for us (and I know not everyone's usage is gonna be the same as mine!).
That's a shame, because I think it looks cool, but I don't like having to take off my case to use the TwinView. And as mentioned before, for some strange reason, Asus designed two different Aero Cases for the phone, and the one that came with my phone covers the air vent.