8K30 is between 1030 and 1188 MHz.
5K60 is somewhere in the 900 MHz range.
Will it work? It depends on the drivers, the GPU, and the display.
That UGREEN Revodok has only HDMI outputs. Do you have a 5K display with HDMI input? There are HDMI 2.1 to USB-C/DisplayPort adapters which could work but it's not a good idea to chain multiple adapters.
That UGREEN Revodok adapter is USB-C only, and supports USB 3.x. That means there's only two lanes of DisplayPort which limits the max pixel clock to < 1080 MHz. It is sufficient if the drivers, the GPU, and the display support 4:2:0 8bpc or DSC @12bpp.
That UGREEN Revodok adapter has two HDMI outputs (uses a DisplayPort MST hub) but macOS will only let you use one of them. A second display would just be a mirror of the first.
A Thunderbolt dock is superior to a USB-C dock - the DisplayPort or HDMI outputs of a Thunderbolt dock will have all 4 lanes of DisplayPort. 4:2:0 or DSC is not needed in that case unless you want HDR or 10bpc.