You penned it Exactly.
The only reason the Belgians were updating their proof rules & powders was an attempt to keep in pace w/ the Germans as the Belgians were supplying ALL the Rough Bored Tubes for the German platforms. The Germans also had a Semi-Smokeless Voluntary Proof and if the Belgians adopted the same process and powder, how could it not be Semi-Smokless? It wasn't till 1911/1912 for the Germans to migrate to a True Nitro stamp and the Belgians may have gotten wind and started their efforts in 1910???
Serbus,
Raimey
rse
