The following Beta motorcycle models appear on the Beta USA web site under the heading "Street Legal Off Road"
350 RR-S, 390RR-S, 430RR-S and 500RR-S ( -S is the 'street legal' designation) all are based on the same 4-stroke engine btw,
so unless your Beta -S was imported into Canada as an off-road vehicle only, then it should be pretty easy to bring that model bike into line with Canadian DOT requirements for a blue plate vehicle.
This would not be a case of a dealer turning a blind eye to the rules so no, it should not reflect badly on the dealer if they are selling blue plated Beta -S bikes, anything else would be very "grey market".
... I suspect the specs are being expressed in metric because they intend to conform to Euro standards which are currently more stringent then N.A.
My Montesa trials bike is street legal in Europe where they actually understand what a trials tire is :| hopefully DOT USA and Canada will also comply with that ruling some day and remove the "off road use only in USA and Canada" tire branding on 1 and 2 ply knobby tires.