Per Repository Group auto-fetch setting

Similar to https://smartgit.userecho.com/forums/1-general/topics/306-configure-background-fetch-interval-per-repo/ but at the group level.  

I have many repository groups and some contain 15-30 repos.  I want them to auto-fetch at different intervals, a few active ones to auto fetch frequently and a few less active ones infrequently.  

Configuring this at the group level saves tedious settings steps.

Suggestion is repo level setting overrides group setting.