I am sorry about that. It's a bug that the customized icon is not shown in EM CC. We will fix it in the coming update. The update feature is not available in the EM CC UI yet but it is available in the command line tool. With the command line tool you can list which extensions have update and update them accordingly. Because we have rewritten the EM code, we don't have enough time to implement the update feature in UI again.
So you have no plans on adding the update button to the gui at all?
We have plan. But the schedule has not finalized.
For me its pretty important but I appreciate its been rebuilt from scratch.
Hopefully we will see this implemented soon rather than later.