In order to support Wacom tablets, TurboVNC includes the GII extension
to the RFB protocol, which basically implements a remote X Input
interface. Thus, it would be straightforward to support various types
of X Input devices remotely from Linux-->Linux, although I have only
personally tested Wacom tablets.
So, can it be made to work? Probably, if the Xbox controller appears as
an X Input device on the client ('xinput --list --long' will tell you.)
Does it currently work? Probably not 100%, because I only focused on
the types of X Input devices needed by Wacom tablets when I implemented
the remote X Input feature. Also, it may be necessary to upgrade the
TurboVNC Viewer to use X Input v2, which is on tap for TurboVNC 3.0:
https://github.com/TurboVNC/turbovnc/issues/156.
If the Xbox controller does appear as an X Input device on the client,
then you may also see it as an X Input device in the TurboVNC Server
session. Comparing 'xinput --list --long' between client and server
will give an idea of where we stand.
DRC