I spray all my dyes, so lap marks are no longer an issue.
You have to flood the surface and always work to a wet edge and blend. What looks bad wet may even when dry.
Water will allow for more working time, DNA dries faster. Water will raise the grain (do not sand this at all), DNA will not.
The final look you want to achieve determines the finish you will apply, not the dye. If your brushing on the finish be very careful not to "drag" the dye.
Tom