Awesome! This one has been sat unsolved in my Best Levels since it was made, numbered blocks always throw me off but it finally clicked in my mind what it was for! :D
The wall blocks with numbers are not used, so I suggest make the square one unit bigger and only one wall block with a number 4 and one immobile wall block. I would also leave the grey and pink blocks unmatched at the start.
I think you missed some unintended solution since I found a solution that doesn't use the small wall blocks: (make a 1x2 grey block and a 2x1 pink block) and stack the pink jelly of the grey jelly which is on top of the long wall block.
I think you missed some unintended solution since I found a solution that doesn't use the small wall blocks: (make a 1x2 grey block and a 2x1 pink block) and stack the pink jelly of the grey jelly which is on top of the long wall block.