I think you need not worry. Folks have been using these things for years, light passing through the felt fogging the film isn't a problem I've ever encountered. Just the usual caveat about loading in subdued, not direct, light. Average room light should be just fine, as long as you're not sitting directly under a 100w lamp.
The only complaint of the Lloyd Lloaders that I've ever heard was of grit getting in the felt and scratching your film. If you keep it clean there shouldn't be a problem. (Why do I suddenly get the feeling I'm addressing a Jr High health class?)