To elaborate on this point: a USB-C dock that includes display connectivity needs to operate at least some of the high-speed lanes of the USB-C connector in DisplayPort Alternate mode. If you split it with two lanes for DisplayPort and two lanes for USB 3.0 signals, then you have halved the potential display bandwidth.
But it's also valid to use all of the high-speed lanes for the DisplayPort signals, limiting the USB bandwidth to the USB 2.0 signals that are carried over separate wires. This is adequate for connecting a keyboard and mouse, but not ideal if you want the dock to provide 1GbE or plan to do large file transfers to external storage devices connected through the dock.
Thunderbolt doesn't always achieve quite the same video bandwidth as raw DP Alt mode, but it allows both DP data and USB data to be multiplexed over all of the high-speed lanes of the USB-C cable, so you can be using more than half the bandwidth for displays and still have enough left over for USB 3.0.
But I don't think the above particularly matters to your use case, because Apple's hardware doesn't support DisplayPort Multi-Stream Transport so the Thunderbolt dock is the only way to drive multiple monitors from just one of the Mac's Type-C ports.
Windows just kinda works on this monitor. It was the same on my last setup too...
I have no idea how macOS does it, but the obvious thing to try is to leave the relative positioning undefined until the first time the user tries to move the mouse off one screen, and assume they're aiming for the other screen.
It would probably make sense to constrain this to horizontal movements, so that taking advantage of Fitts' Law to hit the menu bar or the Dock (at the bottom by default) wouldn't produce a false positive signal about display positioning when stacked display setups are less common than side by side.
For me the macOS Display management experience is absolute dreadful. I had the same issues as the author's and I even had to pay actual money for a third party application (BetterDisplay) to fix some of the issues.
The most infurienting one for me is that I can't disable the internal MacBook display when I am connected to an external monitor without closing the lid. Why you may ask? Because I want to keep using the TouchID. However this is impossible in macOS without an external app.
I will never buy an Apple device for private use.