Not sure what the “friends” does regarding receiving notifications. I’ll add a few of you guys and see what happens. But the “foe” one means you won’t even see posts by someone if you’re logged in.
Edit to add: I bet we’re going to find this forum does everything we need, it’s an actively developed forum. But, I’ve scratched my head on a few topics. I definitely like you’re idea about filtering on both a person and a topic. You can count on anything artem posts being relevant. But Alin posts info about a wide range of things. So, you may not care about, say large assemblies. So, I’m curious if both a topic and person filter is possible.