Separation between heading collections when using outline-mode

[Heime]

When using hide-body in outline-mode, emacs squeezes the headings together.  If 
one has 
outline-blank-line set to t, the headings can be visually separate by adding an 
empty 
line between the headings. 

I want to have the capability of having some headings squeezed together as a 
collection 
(A1-A3), but separated from a subsequent collection (B1-B5), etc, even though 
there are 
spaces between headings.  

For instance, I intend to get

;;; A1
;;; A2
;;; A3

;;; B1
;;; B2
;;; B3
;;; B4
;;; B5

for the following file structure

;;; A1
Some code here with some blank lines
;;; A2
Some code here with some blank lines
;;; A3
Some code here with some blank lines
;;; B1 
Some code here with some blank lines
;;; B2
Some code here with some blank lines
;;; B3
Some code here with some blank lines
;;; B4
Some code here with some blank lines
;;; B5
Some code here with some blank lines