So I
read up more on libTAS on TASVideos.org. Looks like it's a Linux-only tool, so that might limit participation somewhat.
It sounds like the setup is to use libTAS against DOSBox, and run the game inside DOSBox. Reading some of the caveats made in libTAS's
FAQ page, I wonder how usable and reliable this approach is; indeed had anyone even tried it for real for an actual TAS project involving a DOS game? Maybe someone here who uses Linux regularly can actually try it out can report back.
The movie file format of libTAS is at least documented, although a little lacking in some key details. Still, given it's basically a record of keyboard and mouse inputs with timestamps, I guess it should be feasible in theory to translate a Lemmix replay file into their format, though it might be a bit of a pain if Lemmix replays don't record mouse cursor positions (I don't recall for sure but I strongly suspect it doesn't).
To be honest, we have a perfectly good* TAS tool for DOS Lemmings already IMHO, and it's called Lemmix.
I pretty much steered EricLang's initial development of Lemmix with TAS-like support in mind, even though at the time I didn't even know that kind of thing is called TAS. The only "problem" is that technically it's not running the actual game, and there are a few well-documented miscellaneous game mechanics differences compared to the actual game.
*or at least proven to be valuable; I'd concede that general usability is somewhat lacking, and it could definitely use a few more advanced features to achieve true parity with mature TAS tools seen in other platforms like consoles