Thank you for taking the time to help and explain, @bmeeks!
Per your and others' comments in that linked thread, I'm not hopeful that Snort/Suricata would have much hope of working on my SG-3100 even after 2.5.2 rolls around (I'd link directly to your comment but I can't figure out how to copy a permalink on this site...) so I may just upgrade to the SG-6100 since it's Intel-based.
Yes, the SG-3100 is not the best choice right now for the IDS/IPS packages. It is due to the 32-bit ARM processor chip in that box. Because of the 32-bit ARM processor and the lack of Rust support for it, it is not possible to run any version of Suricata on that hardware newer than 4.x. That is two versions behind, and no longer supported by the Suricata team.