I probably have missed it, as I'm not much for the swinging whistles, but I have not seen any mention of adding
operating pops to the Legacy loco (Loco Legacy?) feature set. This would involve essentially randomized (unless you want to
get really freaky) occurrences of sound and "steam", and maybe the steaming whistle mechanism could be used/borrowed.
However, the "steam" needs to come out of the hollow pop valves (little tubes) themselves; the hole-in-the-boiler whistle arrangement looks pretty
lame, as it looks exactly like a...hole in the boiler under a fake whistle, or at least it does on my 2-6-6-2.
Again, I'm probably late with this, and I don't really care, as it's not really my thing, but some would like it.