Yeah I can’t personally tell from Monoprice’s docs if that dongle supports DSC. I can’t find anything saying it does. DP 1.4 has ~26Gbps of bandwith without compression, and ~49Gbps effective bandwidth with DSC. It takes ~11.6Gbps to stream an uncompressed 1440P@120Hz signal. That’s why there isn’t enough bandwidth without DSC, but hopefully there will be if you get a MST Hub that acts as a DSC sink device, like the StarTech ones above.