How do I force x11vnc to stream lower quality?

I need to access a remote machine via a high latency, slow connection. It uses x11vnc and I want it to broadcast video in much lower quality than what's actually on the screen. First thing that comes to mind is to use less colours (e.g. 8 bit), but it can be anything, as long as the remote machine is responsive even though it may, for example, show a large rich-colour desktop image (which I don't need to see anyway). Something [like this](https://superuser.com/questions/411058/setting-up-tightvnc-for-8-bit-pixels) , except for x11vnc. I will, however, appreciate keeping all the text sharp because, I work with the terminal. Here's what I tried: - use -notruecolor, found here http://www.karlrunge.com/x11vnc/x11vnc_opts.html - use -speeds dsl, found here https://ubuntuforums.org/showthread.php?t=1331555 - try setting 8 bit video using -rawfb, found here https://linux.die.net/man/1/x11vnc - enable -ncache 10 as per https://feeding.cloud.geek.nz/posts/high-latency-vnc-tech-support/ , but got [this issue](https://github.com/novnc/noVNC/issues/525) I'm using the built-in Screen Sharing app, which [seems to be almost the only option](http://web.archive.org/web/20180324015551/http://www.davidtheexpert.com/post.php?id=5) on Mac OS. I'm out of ideas. Please help.