I actually contacted Lumintop directly about acquiring a new lens, and Leo responded to say I’d have difficulty doing this myself and offered to send a replacement head for $9 (£6 something for me) which I didn’t think was too bad. 2 weeks later I get a brand new head in the post!
I don’t know at this stage but I’m going to guess it is. I, too, have not seen any mod threads yet. Maybe it is too difficult to?