No blips = no contravention.
As a BB holder you are entitled to park on DYLs for a fixed period, HOwever you mustn't park if there are keb blips, (single or double). The presence of blips tells you there is a loading restriction therefore you must go and find the sign telling you what those are. If not blips are present, then you have no requirement to look for the sign. However, try telling that to the thick and stupid people councils seem to employ in their parking departments.