The Plugable Thunderbolt 3 Dual DisplayPort Adapter is the only solution available out there for a PC to connect to two 4K@60hz displays using DisplayPort technology. We could see how well this works in this review with the Dell XPS 13 9350. However, this only applies to Thunderbolt 3 PC's which have routed 8 lanes of 5.4 Gb/s HBR2 DisplayPort signals to the tunneled through the Thunderbolt link. Unfortunately the Asus Q524UQ doesn't appear to support this.
To demonstrate this, first we connected the LG 27 inch Class Ultra HD IPS 4K 27UD88-W Monitor and an ASUS PQ321 31.5-Inch 4K Monitor using standard DisplayPort to standard DisplayPort cables between the Plugable Thunderbolt 3 Dual DisplayPort Adapter and the monitors.
When connecting the Plugable Thunderbolt 3 Dual DisplayPort Adapter to the Asus Q524UQ, we accepted adding the new Thunderbolt device in the pop up even though external displays connected through the Thunderbolt port still work regardless.
Unfortunately, only the ASUS PQ321 31.5-Inch 4K Monitor is enumerated properly at 4K(3840X2160)@60hz while the LG 27 inch Class Ultra HD IPS 4K 27UD88-W Monitor remains dark.
If the LG 27 inch Class Ultra HD IPS 4K 27UD88-W Monitor is unplugged, the ASUS PQ321 31.5-Inch 4K Monitor will enumerate instead also at 4K(3840X2160)@60hz.
In an earlier review, we mention that the Asus Q524UQ apparently is using NVIDIA Optimus technology. Opening up the NVIDIA Control Panel, we can see that the displays are only connected to the Intel GPU. But with only 4 lanes of DisplayPort connected from the Intel GPU to the Thunderbolt link, only 1 external 4K@60hz display is supported.