2 off since ages and not an inch of creativity remaining... :\
** After a long break **
I finally solved the level. I love the puzzle, but had no fun at the 2 off. In my case, it was no "special" trick but just a matter of ordering the different sets of moves of the concerned zone (I knew where I missed 2 steps). So, I tested different orderings in that zone until I found the one costing 2 steps less than the others.