if the spacer opens sideways, you can adjust. If not, you need to re-cable.
On the listing, the spacers do look solid. More likely than not, they aren't. It would be aggressively retarded as a design choice.
Generally, people have sacrificed bike fit and usability for aesthetics. Especially if you use a bike shop for tweaks, it's becoming luxurious to ride a bike that fits you, because changing a stem can cost the price of car.