For an Awlgrip application we use a high quality dense foam mini roller together with the right mix of brushing thinner and convertor.
Minimum 3 applications with wet sand in between.
We roll only and use a brush simply for corners.
Keep a uniform pressure and wetness to roller when applying.
After about 5 minutes any roll marks will simply disappear and no one will believe that this is not sprayed.
The key is to get the right mix (needs minimum of 1/4 ltr to get right).
It takes a bit of practice so I suggest you experiment
with a small section until you get the right flow so that it tacks off to a flawless finish.
You will also be amazed at how much coverage you get as there is no wastage