Rollers are a really bad idea for a CC... they leave lots of air pockets in the clear and if its not thin enough, then they never come out... never use a roller!

The "thirsty" areas are bare timber soaking up the clear.. this will lead to "grain raise" and will need to be sanded smooth.
Also, make sure the PF is dead level when using KBS.. because it is self levelling ( another phrase for thin and takes a long time to start setting).. it will slide to the lower edge and youll have a thicker coat one end to the other.