Well Forth is possibly the most minimal VM over a platform, as evidenced by openfirmware.
It does have problems scaling though, in that if you've seen one Forth, you've seen one Forth ie. The variations required to fit a platform make them semi-incompatible.
Also, only global scope, no types and no built-in threadsafe constructs are limiting.
That's not to say that a more lispy Forth wouldn't be useful though, in that a concatenative syntax allows us to pass custom datastructures around like APL, and CPS (delimited continuations with lexically scoped dynamic binding would come from the lisp side (see https://github.com/manuel/wat-js).
Memory management in Forth can handle multiple memory types eg. https://flashforth.com/ so adding something like ref counting (https://github.com/zigalenarcic/minilisp/blob/main/main.c) to handle the dynamic list side of things might mesh well.
In any case, if you're looking for a self hosting lisp that runs on bare metal, https://github.com/attila-lendvai/maru has been out for a few years.