Is Hex: Blood Favor good enough to be a Hex perk?
For a Hex perk, its strength is fairly low. 16 m isn't really much at all. The survivor is almost able to run 16 m in the time it takes for you to recover from a hit, so they would be out of that range shortly after you have recovered. It also only blocks pallets, so they still have access to windows to stall for the 15 seconds of pallet blocking. The effect is also wasted if you hit an already injured survivor. Its effect seems so minor yet it's a Hex perk, which lets it be cleansed. It could easily get no value in the time in the time it has before it is cleansed. I only see this perk being useful on specific maps where there is an upstairs and downstairs or when there are multiple survivors nearby.

Comments
Not with it's current values no
It shouldn't be a hex perk. Once you hit a survivor, more often than not they'e going to leave the area they were struck. The only people this would affect are other survivors who are nearby. Making it a hex perk is just a good way to make sure it collects dust.
no. it shouldn't be a hex perk. The only reason it is, I think, is because the other hex perk The Blight has would make even less sense included in his perk set. None of his perks have anything to do with his power, lore, or anything else related, which is not just a little strange, but okay, devs.
As a Hex 100% useless.
If it weren't a hex, or didn't have a cooldown it would be usable I think. It should remain a hex and the effect should follow you around. That way it would be comparable to Devour Hope or Haunted Grounds.