I own a Belkin Thunderbolt 3 Express Dock HD that I have used for 4 months together with a 2017 15 inch MBP. No issues related to this.
1 cable from Belkin to to the Mac, very sweet and minimalistic. 2 hard disk drives connected to the Belkin. 1 Dell non-4k screen connected to the Belkin. 1 usb-hub connected to printer etc.
So, it works for me and feels stable.
Only downside is my suspicion that if I had accepted a total of 2 cables connected to the Mac, a cheaper setup (without Belkin) might have been possible to achieve.
Magnus