as discussed here it is impossible to move a window to another space by pushing it against the side of the screen. I wanted to know if there now is a workaround for this, since it is really annoying, thanks.
The workarounds are fairly well described on the page you linked...
Disable 'Displays have separate Spaces' in System Preferences > Mission Control.
This will re-enable the drag action, if you hit the extreme left or right of the screen pair.
Grab the title bar & use the appropriate shortcut key Ctrl ⌃ [Number] - though this needs setting up in System Preferences > Keyboard > Mission Control. Commands are added with each Space, but not activated by default.
You can also use Ctrl ⌃ ← or Ctrl ⌃ →