Fallback funding sources was talked about since the beginning, it's def a killer feature. 
We have nwc support, but Vlad Stan has also been working on a reverse funding source, that just has a direct websocket connection from the local machine to lnbits, as its usually on clearnet. That'll work very well.
We actually have a big client we are working with at the moment, and for legal stuff they have to run the funding source locally, so need nwc/reverse funding source.