"Sync Now" should be available in the MacOS contextual menu.
It's not very useful to limit "Sync Next" to the "Sync History" tab of the Dropbox menu. There is no way to search for a specific file within that tab, so when Dropbox is syncing over 100K files (randomly, with no provocation from our team), I can't realistically be expected to scroll through every active sync to find the singular file I need to work on NOW. Give me the option to Sync Now in the Finder window where I can isolate the folder or files I need to access.