If you enable this option, automerger checkouts remote branches before merging
Lets assume you have following situation:
~ git branch -a * master remotes/origin/master remotes/origin/release/1.0 remotes/origin/release/1.1
Without checkoutFromRemote plugin automerges only master. Using this option plugin checkouts before merge
~ git branch -a * master release/1.0 release/1.1 remotes/origin/master remotes/origin/release/1.0 remotes/origin/release/1.1