We have three StarTech docks since November or December. No coil whine so far, except for the Realtek NIC (which works out-of-the-box on Macs, but is meh otherwise), we didn't have any issues with it.
I bought two identical 3x 4k docks from Startech, and used them for M1 and M1 Max macbooks. One of them developed a very loud coil whine. No other problems, but it was too loud to be used alongside a dead silent laptop. The other is fine.
Docks are always a hit or miss thing. I had Dell docks before, also ~350 eur or so, and they consistently failed to wake up the external screens on resume from sleep. Same screens worked just fine on the Startech.
