offline compilers can make precise reports that would take too long to compute in a JIT.
For C/C++, lint has been integrated in compilers since long. Luac could implement many more checks while not just compiling. It could support additional notations and provide a way for IDE to integrate these checks by allwing annotations used by the compiler (which would in turn be able to use better optimization as well, knowing that the code will be used in a more precisely described environment that includes also the dependencies).
For now Luac just works on static analysis and JIT in Lua has to make superficial analysis due to time/resource constraints.
Luac also is not meant to be used on small devices: applications are prepared in a more solid environment with much more capabilities than those supported in the Lua runtime.
