Regarding the FSM (Blog) resources...

Okay,
so this is not exactly aimed at the two FSM resource packs being sold here (I do own them both), but rather at the extra stuff they seem to be posting on their blog. I think the English is a wee bit unclear, and I don't trust myself enough to not accidentally mistranslate the Japanese. But I understand it as you are free to use the resources posted on their blog (for commercial games even?) as long as you follow them on Twitter? Sounds a bit weird, so I wanted some second opinions on the matter.

They do have quite a lot of character sheets and other stuff which would compliment the paid for resource packs well though.

Link to the actual blog: http://refmap-l.blog.jp/archives/2018-05.html

Yes, you need to be a Twitter follower to use their newest resources. They also explain why in the follow up sentence, namely that these resources are new and might get updated, so if you follow them you'll be notified immediately when a new version is out.
If you check their VX/2k resources you'll notice that rule is (mostly) absent, because those are old resources and won't get updated anymore.

@slimmmeiske2
That's what I got out of it too. I really like how they keep expanding their new MV resources and I'm interested in those too.

But for now I'm actually mostly interested in their Vx/VxAce compatible tiles and character sets. Do you happen to know what the terms of use are for those? ...and as a bonus question, if there is more of it (under the same terms of use) not posted on their blog?

@Parallax Panda The terms are stated on each post, so it's easier if you look it up yourself. Though I assume it's most of the same.

There's still the old Mack/REFMap resources. I don't think they've all been posted on the new blog. Recovery thread here, also this.
If you meant something else, then no, I don't think so.