Doesn’t matter how smooth your primer coat is as long as it doesn’t show through the base coat (color coat) I assume since you said you have HOK primer that you are doing a 3 step paint (Prime, Color, Clear). In all reality "Texture" doesn’t matter in a prime coat. As far as I know "texture" in primer will not help it adhere to the base coat at all because it is the chemical reaction that bonds the two surfaces together. That is why there are different kinds of paint all of them have there good points and all have there down falls. If there is two much "Texture" in the prime coat you are going to feel more prone to laying on the color coat thicker. The high spots will give you a lighter shade where the low spots will give you a darker shade because of the thickness. Some colors it matters (Yellows, Reds) but depending on the shade of blue you are going with you could be fine you could be in trouble. Lighter shade you will want to be as smooth as you possibly can and a darker blue will be more "Forgiving" Just make sure that each coat is FULLY cured before the next step or it will never cure because you will seal it in and it won’t be able to breathe to cure any further. Nice way of testing this is in a hidden spot underneath the tank or fender do the fingernail test. Lightly push your fingernail in if it leaves a mark it is not hard enough yet, needs more time to cure. And last but not least when you are done DO NOT wax it till next spring. DO NOT use anything but soap and water to clean it and only use water that has VERY LITTLE pressure behind it. Like a genital shower. Cleaners and wax will clog up the pores and not allow the paint to fully cure. Because in reality it will take months for your paint to breath and cure to its fullest potential.