Is there a way to mark all site content for sync on source s

I am trying to copy images, pages, templates, etc. from a dev site to a staging site.
Is there a way to mark everything for transfer via site sync?

The UI seems to only allow for synchronizing content that has been updated. Is there a sneaky way to get all content marked for transfer?

Example:
I have 5 page templates in my source Work site and I want all of them copied to a new destination Staging site. None of the templates show up for sync content selection until I make some kind of change to them. I have to change something like the "Developer name" property of each of the templates, one at a time, in order for them to show up in the "What do you want to sync" section of the Staging and Syncing page.

Similarly, if there are 30 images I need to move to the staging site, I have to make some kind of trivial update to all of them (like apply a new tag) in order to include them in sync.

It would be a lot easier if there was a "Sync all" option for each content type (pages, images, templates, events, etc.).
In the absence of that feature, I was hoping there is a DB field (some kind of last_sync timestamp) I could tweak to get all content recognized for site sync transfer.  

Thanks for your help.

Hello Matt,

Only the updated content is marked for sync or by just republish them. Normally there is no reason to sync the content that is not updated.
As one of the SyteSync prerequisites is to have the same database and configuration, except the connection string when set-up it and in order to move all the content from once server to another, you can just copy the project (files and the database) on the source server.
Than you can set-up and start sync the content from now on.

Furthermore, migration of content between different projects and/or versions is not supported. Supported SiteSync scenarios are described here:
http://docs.sitefinity.com/one-way-synchronization-scenarios

Regards,
Svetoslav Manchev
Telerik