You can use Tableau's web edit functionality to edit the dashboard directly on Tableau Online. It has most of the same functionality as Tableau Desktop, but not all, so for some changes you may need to still make them on Desktop.
In Tableau Online, when you have your viz pulled up, click the "Edit" option on the top right. That'll bring you to the web edit area.
Hi Paul, thanks for your response.
And to keep my local .twb file updated, I'd have to download it as workbook after editing it online? Won't that break all the references to extract locations, etc?
Yea, once you redownload it you would have to reconnect to your old extract.
You could also update your desktop version with the same updates you do on your web version to keep them in sync. It's not an elegant solution, but it's the only way to keep from having to upload your extract each time.
Just checking this resolved your issue?
This is a workaround, it works, but I don't consider it a solution, that's why I didn't mark it as the Correct Answer.
Good stuff, thanks Daniel