The first minute or two of the video 
No, I donāt think this is possible currently. The tool that behaves the closest now is the Polygonal Lasso, but it only selects in straight segments.
What weād need here is a combination of these: Freehand Selection that has āno auto closeā mode, like the Polygonal Lasso.
Maybe someone can make it happen. It could be a toggle on the current Freehand lasso tool.
EDIT: I overlooked the significance of the CTRL key 
I agree, this is basically exactly whatās needed here, just without showing a āpreviewā of the straight line if the pen is lifted.
@Elixiah, I think you are a wonderful and very skilled Krita Artist, please forgive me if Iām saying things you already know, but in case you donāt knowā¦
Have you tried the Magnetic Curve Selection?
The action is not as smooth as in the video, but it looks interesting to me, you can do only corners, or also some intermediate points or also some freehand, even if itās important that the corners are selected.
[EDIT: better explanation]
What is important in the video I think is that the tool follows the line of the drawing between the freehand sessions, itās not a straight line, this is done by the Magnetic Curve Selection in Krita, ā¦maybe the Anchor Gap could be lowered below 20px to have a more freehand feeling and not risk to not having the anchor in the extreme corner.
EDIT: I was wrong, there should be a straight line between freehand sessions, see the beautiful full explanation here: Contiguous Freehand Selection Tool? - #29 by Someonesane
Really? It didnāt seem like that to me, but I didnāt watch the whole video.
Ehmā¦ watching again and Iām not so sure itās not a straight lineā¦ 
Oh wait you right it is a ctrl . I think they are straight. Sorry for confusion 
@Skess01 I havenāt tried the magnetic Curve selection tool on a line. I have used it on solid colored objectsā¦ Iāll have to experiment.
I have to disagree on that point. The video showcases the Procreate App, which doesnāt have a magnetic lasso feature.
I use both Procreate (the app showcased in that video) and Krita, nearly daily and use the selection features in both for creating shadows and filling in color flats for comics. That saidā¦
Having reviewed the video (specifically within the timeframe you noted), itās my opinion the feature youāre seeing in Procreate works like Kritaās Freehand Selection Tool. Only, with Procreate youāre allowed to lift your pen off the screen (which is because itās a touchscreen tablet-based app, so the pen isnāt tracked in the same way a display tablet is for a PC). When you place the pen down again, a straight selection line is automatically connected between the point you lifted your pen up, and the point you placed the pen down again. The closest thing to that in Krita was previously noted by the others, where you use the Freehand Selection Tool to start a freehand selection and, when you want to lift your pen, youād hold Ctrl down. Youād then place your pen at the next position and release ctrl. This action essentially results in the very same selection style but requires the modifier key to work.
Each applications method for this has drawbacks for me. While itās nice not needing to hold a key down to lift your pen in Procreate, it often leaves me searching for the point I started the selection, because you must click the node to close the loop. The reverse, as Krita handles it, can also be troublesome, because if you just carelessly lift your pen, the loop will atomically close with a straight line and could lop off other areas of your selection by mistake.