I'm familar with BUE 2010 R3 and BUE 2014's interface is both new, options are changed and some things are sort of gone (no more selection lists? They are servers now?)
I discovered that my Full backup to disk part of a synthetic backup plan did not change the archive bit on a large backup. So I found the job default for B2D and changed that to archive bit vs mod time but I cannot find the same option in the job defauls for synthetic. Under "Files and folders" it simply doesn't have the dropdown to change from mod time to archive bit that was there in the B2D defaults. So can I run a synthetic with archive bit or not?
A synthetic backup feature is catalog driven. It does not use modified time or archived bit as regular backups do.
Use Storage based catalogs must be enabled in global settings and "Collect additional information for synthetic backups" option must be enabled in the job settings for a synthetic backup.
I found few KB articles written for older versions of BE, however the content logic remains the same -
This may be useful as well - https://support.symantec.com/en_US/article.HOWTO99539.html