We currently have our App release in the US and demo in the other regions. We've just seen there is a new Mobile SDK (0.5.0), should we be updating and then resubmit the builds or are they good to leave as they are?
You don't need to submit an update every time we rev the SDK. If there's some critical problem (as there was with Android 5 support), we'll reach out and ask for updates. Otherwise, you can leave the current build you have as-is.
However, next time you submit an update it should be built against the latest SDK.