I don't care if it's easy; suggesting Lua as solution is dissembling. I complained about poor tooling that doesn't follow defacto standards when the device it's running on could easily handle having a more common, older, standard bash than choosing some castrated shell.
If it were a forced choice, because of hardware limitations, of having Lua or bash, I could get it. Lua is more capable. But in this case, it's not a choice of either/or; the device could easily handle both.
BusyBox is, as I understand, configurable for how "complete" it is. That's why I say it's lazy to pick some default minimal compile when it could be more accessible, and less of a pain in the ass for users.