I believe this is now the smallest flip flop in the game, by pixel count.  By element count it has 5.5 elements. 1 in, 1 out, 1 BTRY, 2 CRAY, 1 intermittant INSL.

This device uses layered CRAY to move CRAY's output one space away from the CRAY.  In this case, the top CRAY produces one particle of properly spaced INSL, while the bottom CRAY provides the masking particle for the top CRAY to delete.  Both CRAY are set to produce INSL, but the bottom CRAY's ctype output is rather meaningless; it could be anything.  Bottom CRAY is there only to mask the top CRAY's output and produce that necessary space. 

Thanks, for explaining it.  :)

I posted this elsewhere, but in case you check here first.  This meets the criteria you specified.  Would you take a look and see if it's actually a flip flop?  It's 3 pixels and sparks to opposite sides every frame.  You can verify this by putting ARAY on each side and watching how they act. So spark from same pixel position every two frames.

Thing that I'm not sure about is if a flip flop has to be able to accept control once it starts.  This one runs until you delete a piece. Might be something different.