Hey Skipperoo!

Thanks for the reply.

Firstly, I 100% agree with you that the map should show both names. Unfortunately, one of the limitations of the default OSM renderer is that only the value in the "name=" field is rendered. Ideally, the 'name' and 'alt_name' field should be rendered.

The signage along this section is inconsistent, yes, but most of the signs I've seen look like this https://www.mapillary.com/app/?pKey=272912654578868

where both names are shown. This is the same as how other dual names roads are signposted. 

Lastly, with regards to addressing; the source I am using for addressing is the Vicmap data, which is the official, "authoritative" source for addresses. These stores might choose to use an address other than the official property address (c.f., shops that advertise their address as "the corner of x and y"), but the underlying property is still assigned Dandenong Road.

Happy to explain further if you like.