Hello there

No, unfortunately /pet focus doesn't work with any client (although /pet hold has been fixed to work now also on Underfoot client).
It's a real problem for major pet classes as soon you fight aoeing mobs in a raidencounter as you cannot force your pet to stick on your wished target (e.g. your pet will constantly switch to the aoeing boss mob even if you wanna finish that add down first called by your tank/MA).
You can ease the problem a little bit by making an attack hotkey which clears your pet's hate list each time you tell it to attack (line 1 /pet back off line 2 /pet attack), but it does not replace a /pet focus command and works only moderately well (if your pet is tanking and mob A hits harder you won't be able to send pet on mob B, the add you wanna kill first).
This issue was already explained several times and devs said they would have a look into it. Let's hope they can give us soon /pet hold, I really do miss it
