The horizontal rotary glow discharge polymer (GDP) coater is being developed to help increase the production rate of inertial confinement fusion targets and to meet the very high production rates needed for inertial fusion energy targets. The coater is used to put a conformal GDP gas retention coating on top of foam shell targets. A number of alterations to the design and operation of the horizontal rotary GDP coater are discussed. Compared to previous iterations of the horizontal coater, the changes have resulted in improving the yield of gas retentive targets with thinner coatings and increasing the coating rate, smoothness, and uniformity. The number of targets that can be coated at once has increased from tens to hundreds, or even thousands. The alterations include changing the coating tube configuration; adjusting the coating pressures; and altering the radio-frequency power, gas flow rates, and tube rotation rates. Methods to further improve the coater are also discussed.