I've always thought the Curse was a 'electical/energy' curse and less so of a tech curse. Muskets would work in my opinion because it is simply sparks and minerals causing an explosion. When you break it down, it's very little to do with 'tech'.Â
If it's being put towards a vote, I say it affects the energy/power itself, and not the actual workings of the tech it's powering. Thus why something like magical clockwork gnomes migh work, while giant robots powered by nuclear generators won't. Both are rather 'high-tech' for Militeregnum, but one is running off of the "Terrible outsider power of electricity" while the other is simply running off of Magic.
Does that make sense to anyone other than me? :P