GMforPowergamers
Legend
I'm guessing it's the effectively unlimited teleportation that's concerning you, since the rest of the blink dog is line with the other creatures
What if you removed the recharge from the blink dog's teleport feature and made it 2/short rest? Or whatever number works best for you.
I guess looking at it, I may have had a knee jerk reaction, you are right they are all low (1/4cr just like the ones the warlock gets) and I guess it isn't more powerful then an imp being the perfect invisable scout...