yes that sounds like a nice idea. I'll have a look at that in a future version.
the xl_func decorator uses the 'func_name' property of the function so you could try changing that before applying the decorator and that should work, e.g.
test.func_name = "a.b"
test = xl_func(...)(test)
or with another decorator:
func.func_name = name
I'm afraid I've not tried the above code, but I think it should work. Let me know how you get on.