I don't have any link on hand right now for a writeup, but I've followed yabai's (https://github.com/koekeishiya/yabai) development closely ever since it was called kwm and saw the limitations of macOS's public API to managing windows.

The windows with this parent process go here thing can be solved easily, and can even be done as a one-liner with yabai. Example of moving all the windows of Sublime Text to display 2:

    yabai -m query --windows | jq '.[] | select(.app == "Sublime Text") | .id' | xargs -I '{}' -- yabai -m window '{}' --display 2

It can even be automated by adding a rule in ~/.yabairc (although that might be undesirable as it will always be enforced even if you want to move the window manually):

    yabai -m rule --add app="Sublime Text" label="sublime-display-2" display=2

Yabai can also resize the window to whatever size you want, or move it to a specific space, and it can even do that based on the window title.

It has this much power because it uses macOS's private APIs from SkyLight.framework (the macOS window and display manager): https://github.com/koekeishiya/yabai/blob/master/src/misc/ex...