An iMAC can be used as an external monitor using Target Display Mode. Is it possible to get a DisplayLink dock to enable TDM when iMAC is plugged to the dock (i.e. using a Tunderbolt 2 to HDMI cable)?

For example, I have a MAC Book Pro 13inch (2016) and an iMAC 27inch (2012). I use iMac as an external monitor using TDM with MacBook Pro (using a Thunderbolt 2 to USB-C cable) as described on https://support.apple.com/en-gb/guide/mac-help/mh30822/mac

I also have a Dell DA300 displaylink dock. Using Tunderbolt 2 to HDMI cable to connect iMAC to dock and USB-C from dock to MacBook Pro does not get iMAC display to switch to Macbook Pro.

I'm unsure if someone has already suggested this, but with the latest update Mac has rolled out (for Catalina 10.15), my DisplayLink stopped working with dual screen.

I have updated the driver to the most recent release, and all that would display would be one of the two screens. DisplayLink lists a possible solution involving entering recovery mode and inputting commands, however, I am impatient and lazy and did not do that.

But, I did get my dual display working again. For me, toggling my displays to mirror activated my dual screens, and toggling off mirroring has left my dual screens functioning as they should.

I don't know if this will work for anyone else, but it did for me, and it took 2 seconds to test, so it might be something to try before rolling out recovery mode.

On macOS 10.14.6 (2017 MBP with i7, DisplayLink running on i-tec USB-C hub), DisplayLinkManager takes up to 5-10% when supposedly idle. When running audio software - namely, Ableton Live and Reaper, but likely this can reproduced on any audio software and DAW - DisplayLinkManager can take up to one full core (~95% CPU reported). This doesn't seem to be related to the size of the project, so even small projects that take up 15-20% CPU are massively affected by this issue.

Native Instruments Kontakt has an even weirder behaviour:
- restart MBP
- connect external monitor via DisplayLink
- try to run Kontakt (actually, ANY NI app, including Komplete Kontrol, Maschine and Creator Tools). The icon bounces in the dock and the app doesn't start at all.

Oddly, if you run Kontakt BEFORE connecting the external monitor, it will work fine. If you quit Kontakt after connecting the external monitor and relaunch it, it will open just fine. This issue only happens if you open Kontakt for the first time in a session while having the external monitor connected.

DisplayLink is currently unusable in a real-world music production scenario. Please fix!

Further details:
Focusrite Scarlett 6i6 audio interface. CPU drain increases by around 10% when using external USB audio interfaces regardless of their manufacturer/drivers, which is unacceptable but seems to be only part of the issue.
Tried to remove all the peripherals connected to the USB hub to no significant improvements
Using HDMI port, only one display connected
Tried on and off battery power

The Linux Foundation is the place to get things into the kernel. They will help you integrate your hardware into the mainline kernel without compromising any internal IP you may be worried about. Its really the only way to get a driver working for any OS. Work with upstream not against it.

This translates to Windows and OS X as well. I was frustrated getting my device working with Windows. Complete pain and not plug and play by any means. OS X Mojave doesn't work at all and Linux shows the same behaviour. Flickering on and off rapidly an when looking at system logs it seems to be in a constant connect / disconnect rapid loop.

Open Source the whole driver stack and work with the upstream OS developers to get support built into the kernel will make your hardware plug and play on all operating systems.