Lets break this down into
1) Finding candidate DUTs in the lab.
2) Attaching displaylink adapters/chameleon.
3) labeling them with either chameleon_hdmi or chameleon_dp_hdmi
4) starting to run tests by adding an entry to
chromeos-admin/puppet/modules/lab/files/autotest_cautotest/suite_scheduler.ini

Adding some people who have hopefully more knowledge on how we get the hardware in the lab.

BTW, is chameleon already supporting this kind of connection? 
(USB->adapter->HDMI->chameleon)

It depends what you mean by "supporting". Chameleon itself doesn't care where the signal comes from.

However, we will have other issues on the sw side, for example around color accuracy (IIRC udl uses RGB565 only so the colors will not be as accurate) and the fact that the display driver is a different driver than the main one.

kalin@ or rjahagir@ may help.

Re c#1, the label chameleon_hdmi is already used. Due to the limitation of the test infra and the dashboard, labeling this special Displaylink devices to the existing label will affect the existing test suite. You can't tell which one is Displaylink; which one is normal. May create some new label for this purpose.

I found some of the DUTs seems idled for some time.
For example, chromeos6-row3-rack3-host1, chromeos6-row2-rack21-host16, chromeos4-row8-rack13-host14, chromeos6-row21-rack2-host1 on pool:suite has been idled for a long time.
As they are idled for some time, I guess no body will complain about it. Are there any other concerns for attaching those with the displaylink adapter?