Can the Xfce window manager (Xfwm) provide window previews/thumbnails (for DockbarX for example)?

[N. W.]

Hello,

the DockbarX developer recently said, that he is going to release a new
version of DockbarX soon and that he is making sure that it will work
with the xfce4-dockbarx-plugin, see:

https://bugs.launchpad.net/dockbar/+bug/1329244
https://bugs.launchpad.net/dockbar/+bug/1314868/comments/5

So, I asked him if he could make the window previews of DockbarX work
with Xfwm (the Xfce window manager), see:

https://bugs.launchpad.net/dockbar/+bug/1329241

However, as you can read there, he said he does not know if and how
this would be doable and asked that if there is anyone who knows how to
do it, to please tell him how to do it.

I had a look at the Xfce bug tracker and found some similar questions:

https://bugzilla.xfce.org/show_bug.cgi?id=6884
https://bugzilla.xfce.org/show_bug.cgi?id=7318

However, unfortunately nobody replied to them yet.

So, therefore I would like to ask on the Xfce mailing list:

Does anyone know if Xfwm (the Xfce window manager) is capable of
providing window previews / window thumbnails for things like DockbarX
for example?

And if yes: How?

And if not: Why not?

It would be much appreciated if someone could answer that (even if the
answer would be "Unfortunately it's currently not possible").

Regards