@just nick,
the barberpole (vmo limit) does indeed move with flap extension, just like the clacker indicates overspeed for current flapsetting.
The clacker only sounds when > 5 kts overspeed is achieved, thus beyond the first red bar on the pfd-barberpole.
During flap extension though, the clacker can be a little cranky and sound momentarily although no overspeed condition actually exists.
I loved flying the CRJ, have fun....