Indeed, if you add C code and that crashes it maybe harder to debug than a pure C system, however it wasn't my experience while developing DeviceScript - it was either clearly a bug in C that didn't really depend much on the bytecode, or an exception in DeviceScript which you debug just like in TypeScript.
We also support Jacdac [0] which makes it possible to put the C code on a different MCU, isolating the problem and adding traceability. (You can also run Jacdac server on the same MCU)
