I'm afraid it can't be game changer. In years of war Ukraine has developped lot of cool things to depend less on Western supply. Besides Flamingo, there is also Neptune or Trembita missiles. But main problem is production. Ukraine need lot of such missiles to change things, but they can produce very little of it. This is why we don't hear often about successful attacks using their own made missiles. It's hard to make big production when your military factories is one of main targets of Russia.
From what I see Ukraine is doing big production of cheap attack drones or Bohdana howitzers, but when it come to missiles, its' more complicated question.