I had mentioned that in a few other posts. Along with advantages versus Surface Book docking. And versus non-lap-mode alternatives, or no angle-djustments for current 3rd party "universal" lap-mode solutions for tablets. Nor support for Hi13/13.5inch lap-mode otherwise. Or other disadvantages of not going for a detachable tablet with decent lap-mode support.
If counter weight was additional feature hardware like the Surface Book more expensive performance base keyboard, then latching and unlatching would have taken longer. And more expensive keyboard base, in this segment of the market, even less would buy the keyboard it seems if it were more expensive even if had more features in it to make the counterweight packing more features than mostly counterweight. Not forgetting quick unlatching as is the case now.
See some Hi13 overview listing advantages of combination with this keyboard (mainly lap-mode, literally on your lap sitting "anywhere" typing, while still detachable, stating just in case you forget this is the best companion to the Hi13 TABLET):
And consider the rotary keyboard for all of lap-mode benefits (see Laplets vs Tabtops in forum search) and quick latching/unlatching and no BT stuff (pairing, reconnect time, some lag also in characters apearing compared to USB or pogo connectors, keyboard standby mode, etc.. it's relative).