It appears the smeltery registery fails with the British spelling of aluminium.

This can be worked around by changing all the json files, but I think a more elegant way (to make the default configs work) would be to inject some special logic into registerMeltingChunks() to handle the spelling differences. Here is a fork where I've made the change.

Good catch, Thank you ^^
copied it over into the main brach, didn't bother making a PR for that single file change.
Sadly I saw it too late and I already finished up the 1.3 version on curse, so next version it will be fixed ^^