Did you take his advice and join their discord? You would probably have the best chance of finding people who know about modding SMX there. The discord link in that thread is
https://discord.com/invite/6P67kJP
I would say it's not that people don't want to help but rather there aren't that many people that do modding (relative to players), and even fewer that use SMX. And people who do modding have their own mods to work on.
I've never used SMX so can't help with that, but I looked at your other topic and noticed all those "did not apply" errors. In my experience that means you're trying to change something that doesn't exist, which is often an error in the xpath string where it doesn't lead to a node (like a missing slash, or mispelled node level).