4212 driver seems fine. It's a windows update driver so I suspect we may get it soon anyway. To install manually, decompress the cab, use the have disk method. I don't see any pros or cons with this driver so far. Of course, haven't spent more than 2 hours with it. I did it over lunch.
I updated to 4212 and I can confirm that DaisyChain is still broken and it also breaks my second monitor using USB 3.0 DisplayLink dock. I rolled backed since I was at work. I was so hopeful, yet getting used to the disappointment.
What is everybody else using to drive multiple monitors through the Surface Dock?
My setup.
Surface i7 (have tested this each build since 10074)
(2) Dell U2414H Monitors
From Surface Dock to Monitor 1: Mini-DisplayPort to DisplayPort
From Monitor 1 to Monitor 2: DisplayPort to Mini-DisplayPort
Monitor 1: DP 1.2 Enabled
Monitor 2: DP 1.2 Disabled.
Dell Display Manager: v1.24.0.1582
My problem.
With the above setup, if I power on the Surface both external monitors are dark, no video, nothing. If I power down Monitor 2 then Monitor 1 comes on line. Monitor 2 will not come on for nothing. I finally had to run Monitor 2 through a USB 3.0 DisplayLink Dock to get to work.
With the above setup DaisyChaining works flawlessly with my 8.1 Surface i5 in the Surface dock.