The sale of 243 is probably going to depend on RCMP more than how fast HK can deliver. The 243 and MR are in abundance in Europe.
There is no factory HK bbl. They are either cut job in the US ( not legal in Canada) or something new made in the US.
Go visit the online European gun stores and you can see what it is available. So far I have not seen a single 14.5" MR223A3.
It is probably something with a SKU in the factory that can be ordered, but HK has not made a run yet. It took them almost a year to deliver the first A3 version in Europe.
So far I have seen MR223A3 16", MR308A3 16" with G28 kit, MR308A3 20" with G28 kit and MR308A3 16" patrol.
I do hope NS will get the MR223A3 in 14.5" with a lighter barrel to save the trouble. About factory 11" , to be honest, I won't get my hope's up. I read it somewhere German government has deemed it to be "non-sporting" and won't allow HK to market it to the German civies. I don't remember seeing German gun store carrying anything shorter than 14.5" ish. The German government seems to be amazingly rigid in dictating people outside of German will get exactly what German civilian can get.