No. It is too slow. Almost two separate movements needed when on the other side is just waiting with hands up or head movement or counter or...
But great for set up. I also use vertical back fist (upwards and downwards). As alternatives to the jab. Better with footwork and without overuse it, since we expose a lot of our body (not as safe as a jab).
Backfist upwards seems invisible for the opponent. Often, they just take the first one on the chin without any sort of reaction! But no power the way I use it. It is set up for low kicks or hook.
As a power shoot, maybe only after a fake spinning back fist (which works as a setup, hiding half of the movement and putting the opponent's defence on the other side). I have seen that, but not used lately.