Characteristics of TN LCD shutters/light valves
The LCDs are all about the name. Liquid Crystals = Crystals in a liquid that are steered around by voltage bias applied between electrodes. The frequency range supported by the devices is related to how fast the crystals can be steered in their liquid medium. You will not be able to change that from what a manufacturer has specified. 

Also be aware that LCD crystals move slower in colder temperatures. Often times this can become very obvious if you watch the LCD's on a gas pump in -10F or -20F weather (some equipment applies heater pads to the back of the LCD glass to help with this problem although that would clearly not work for a glass used as a transmissive shutter).