Let's say I have an issuetype "Bug" that is used in 2 of my 10 projects (controlled by issuetype scheme).
I want to add a new customfield and have it available for all bugs.
In my customfield configuration I select Bug as the only isuetype. Is there any benefit in also restricting project?
The benefit of leaving project global is next time I add bug to another project I don't have to think about updating the custom field configuration.