In the Thai sub-forum, there are some threads on the mapping quality of facebook and grab - sadly in a very emotional and exaggerated style. Still, an important hint can be taken from there:
adding a non-existent connection of roads to the map actually causes more trouble than missing an existing connection.
The imagery can often be misleading, and some “local knowledge” may help, e.g. when “gated communities” can be detected.
I’d also suggest to collect GPS traces from rural areas and upload them (still most of the GPS traces in Perlis outside the main roads were collected during my tours on bicycle…). That will help to better align the current imagery. And perhaps help the imagery providers to better ortho-rectify new imagery before release.