The manufacturer's homepage says "1 x 4K HDMI port - 60Hz". I don't know if the Hz number could be higher at 2K. But I doubt it. The manufacturer also says that on certain Macs only 30Hz is supported at 4K. A clever marketing department would then surely also mention if even 120Hz or more were possible at 2K. My 2K monitor also displays 60Hz, but I don't have a TOP HDMI cable at hand. Maybe ask Satechi directly?

Btw (if not already known): More than 60Hz refresh rate makes sense mainly for gaming. This has nothing to do with "flicker-free". That depends more on the display (e.g. display lighting). Even the top screens from LG (Ultrafine) only deliver 60Hz on the Mac via Thunderbolt.