I like Patrick Laborde's response. As the count of the suit is evident from the bidding, coming back the 5 of spades, in general principles will help partner to find the correct switch (in our case club from Qxx)
I don't know about regionals and sectionals but I can tell you the feedback I receive for the nationals: People from Europe and Middle-East are less inclined to play in a national because they find the atmosphere more hostile(opponent's behavior, director calls and rulings etc) than the ...