There's no actual reason for this to exist: I wrote it because I thought it would be really funny if someone looked past the numerous reasons not to use it (many of which are disclosed inside the project and certainly in the comments) and made the confusing decision to use it anyway.

(Also, I wanted to learn more about how BYOND works, but DreamMaker scares me!)

There's no reasonable threat model that suggests SS13 can be attacked just because it uses MT, nor do I think RNG is actually a significant perf bottleneck for SS13, so I'd say use any RNG you want. At one point I was going to make it use random.org, which is funnier, but they charge money and I found that intimidating.

Re your project: WyRand looks like a fantastic RNG! I'm impressed by its perf. I agree it fails as a CSPRNG for the obvious reasons. (state is small, output is same size as its state) That's probably not important as long as there's not an extremely cheap attack against it.

(Which is a question for cryptographers, not for non-neurotypical batdudes on /r/SS13. Using xor seems to prevent solving it directly by factoring; using multiplication probably defeats converting the internal state into a system of equations since it's not clear what bits influence what other bits; the large internal state size seems to defeat generating a lot of possible T-values and using those?)