I've created a script for Ubuntu (suggest 20.04) or Debian linux which should automate the setup, configuration, and install of a ckproxy to mine on the solo pool, though you can edit it afterwards to mine wherever you like. I do not suggest using something like an RPi as you want reasonable performance from your proxy to avoid any added latency.
Download the following script:
http://ck.kolivas.org/apps/soloproxy/setupsoloproxy.sh
It will not be directly executable, so execute it with
sh setupsoloproxy.sh
And follow the prompts. Tell me how you go.
I have a dumb question I hope you can answer, What argument do I use to change difficulty for your pool? is it only by port? ive never used an s9 before and ive tried d= diff= --suggestdiff but non seem to stick.