Hey Leroy,
Can you give me a specific example of what you’re trying to do? It’s definitely possible to load iframed content using the featherlight script, but it’ll probably make more sense if I can demonstrate it on something you’re familiar with.
We do have plans to create some detailed instructions on extending featherlight to do more advanced things, but in the meantime I’d be happy to try to get whatever it is you’re struggling with working.