Can anyone confirm walking buddy w/ Eevee trick for Espeon or Umbreon

Buddy trick definitely works, I've done it 3 times and know others who have done it. Just make sure you evolve it while it's still your buddy so the game knows you've walked it 10+ km.

Worked twice for me just make sure to leave Eevee as your buddy when you go to evolve him.

Save for Vaporeon

Make sure it drops 2 candies. 10k straight is best and evolve without changing buddy (as stated above). Evolve during daylight for Espeon. Worked for me 3 of 3 tries.

Tested myself. Worked.

I've tried it twice. Failed both times.