That person could have been me. I have an MST Display Port splitter as well.

https://www.i-tec-europe.eu/index.php?t=3&v=492

You can connect two monitors and extend your desktop on both. Works like a charm in Windows 10 via Bootcamp on my MacBook 12-inch. But unfortunately Apple never enabled MST support in macOS for Intel GPUs or via USB-C, however the built-in hardware supports it. Running USB-C in alt-mode gives you direct Display Port access. The MST standard has been around since 2009 – came with Display Port 1.2 standard. It's just Apple...

If you're a lucky owner of a Mac with a Thunderbolt 3 port (which I am not :( ), then you can run two displays from a single port. Not sure if uses MST or something else though.

It seems Apple is pushing aggressively Thunderbolt 3 as the only option for any accessories. But that reminds me of the sad story with Thunderbolt 1 and 2. The docks were expensive, hard to get, and with the 10.13.4 update eGPU solutions were rendered obsolete. :)

If you ran an eGPU from your TB1/2 port you ended up with a blank screen as well last Friday.

So no solutions for people that have thunderbolt 2 and usb 3.0 on a MacBook Pro?

Geez its getting worse at every corner.

How do you get USB-C to run 2 monitors in extended mode? Without MST they are simply clones with display port. With windows they work extended.

I just installed the DisplayLink v4.3 driver (mirror only) and it's at least working for me. Any news on how the "extended display" driver update is coming? and when it might be released?

Thank you,

My solution for today
 

Here is what I have done to get something working for myself again. I run 2 40" 4K monitors off my 2015 Macbook.

The first display is off the HDMI port from the AV adapter. The second display I was able to get back up and running by moving to the 4.3 Beta driver that only supports mirror mode. I then opened up the clamshell (which I usually keep closed) and load up SwitchResX. Now I can mirror the clamshell display which I can now set to run at 4K. So I have 3 displays (sorta) running on my macbook 2015 while I ignore the TEENY tiny fonts on the clamshell display itself.

Its not perfect, but why i hadnt thought about it before. Least I have 2 monitors again
Apple TV + HDMI = 2 monitors!
https://i.imgur.com/7GaGLNZ.png

Such a pain. I switched to the Dell WD-15 dock as that doesn't use DisplayLink. It gets me one external monitor, but not two, even though it has the capability to run two monitors in Windows. It seems that Apple limits it to a single external display on a thunderbolt port for some reason. The only solution I've been able to come up with is buying two Thunderbolt (USB-C) to Display Port adapters and I will have to plug in 3 cables when I dock.

Yes Apple, unlike Microsoft, does not support MST through TB. Its an OSX limitation. This means you get mirrored monitors on TB but not extended.

According to this product, macOS does only support dual monitors on a single cable via TB3. I'm not sure if it's MST. But see for yourself: https://www.i-tec-europe.eu/index.php?t=3&v=480

I get cloned screens when I connect an MST adapter via USB-C (USB 3.0 Gen 1) on my MacBook ( not Pro). The pro models have Thunderbolt 3 ports so it should work as pictured on that site.

However, using a MacBook 12-inch – which only has one USB-C port – a DisplayLink docking station was the only solution to connect two external monitors via a single cable. It was the perfect single cable solution until Apple broke it. :(

How to select which monitor is cloned
 

So I'm using the 4.3 beta driver on my 10.13.4 system and had clone mode working fine for a day. Then I put the computer to sleep and woke it up and now it wants to clone the wrong monitor. Its cloning my external display and not my built-in display. Anyone know where/how to change that and choose which one is cloned by DisplayLink software?