nxagent 2:3.5.99.21-3build1 (armhf binary) in ubuntu focal

 NX is a software suite which implements very efficient
 compression of the X11 protocol. This increases performance when
 using X applications over a network, especially a slow one.
 .
 nxagent is a nested Xserver providing NX transport of X sessions. The
 application is based on the well known Xnest "nested" server. nxagent,
 like Xnest, is an X server for its own clients, and at the same time, an
 X client for a system's local X server.
 .
 The main scope of nxagent is to eliminate X round-trips or transform
 them into asynchronous replies. nxagent works together with nxproxy.
 nxproxy itself does not make any effort to minimize round-trips
 by itself, this is demanded of nxagent.
 .
 Being an X server, nxagent is able to resolve all the property/atoms related
 requests locally, ensuring that the most common source of round-trips are
 nearly reduced to zero.