That's the thing, though... much stuff outside the specialized diet might be an issue and I don't know enough about Lorikeets to have an informed opinion. I'm sure a little treat now and then is fine, as it would be for any parrot, but fresh food, sprouts and stuff in any quantity, I'd want to compare to what we know about their nutritional needs, and you did mention expanding his diet.
We do tend, of necessity, to have a bit of a one size fits all approach to answering these questions. Lorikeets are an obvious exception, but there are others that are a bit more subtle.