Hard to tell whether it supports proper tail calls or not. The readme mentions Scheme, so it's not impossible I suppose! One of the nice things about wasm is the formal semantics; a project like this could benefit from one of those, too.
Author here, Tail calls can be implemented in MiniVM bytecode. There was once an instruction that performed a tail call, It bit-rotted due to not being used.
MiniVM is moving very quickly currently. A lot still needs to be done, like JIT and optimizers.
Eventually a formal specification of MiniVM should happen, just not yet as things are changing too fast.
