I know this post was originally asking about a different remote, but the Elite screen remote is available in the Harmony database now. Up, down, stop all work great.
JVC RS-520, Elite Screens 100" AcousticPro UHD electric
Klipsch RP-8000F, RP-450C, 2xRP-240S, 2xRP-402S, 2xSVS PB-1000
Onkyo TX-NR585/HDFury Linker/MiniDSP 2x4 HD
Panasonic UB820/PC/PS3/PS4 Pro/Switch/WiiU/Xbox One X
Logitech Harmony Hub