Sort collections manually with collection tree

I would like to sort manually collections using collection tree plugin.

For example, I would like collection C and subcollection C.* to be after collection B. and subcollection A.3 to be after A.2. Such kind of things. The only option of the plugin Collection Tree is to sort aphabetically which is not what I want to do (even if would work in my constructed example). I want to choose manually the order.

Is it possible out of the box or should I modify the mysql table?

* Collection A
  * Subcollection A.1
  * Subcollection A.3
  * Subcollection A.2

* Collection C 
  * Subcollection C.1
  * Subcollection C.2
  * Subcollection C.3

* Collection B
  * Subcollection B.1
  * Subcollection B.2
  * Subcollection B.3

Looking for this feature, too! Any solution so far?

I’m looking for this, too. Any ideas?