I came up with this idea for a sudoku variant based on placing all 36 possible dominos on a sudoku grid.

The geometry of each box is identical and consists of 4 dominoes arranged in a pinwheel around the central cell.

The numbers in the black rectangles show the difference of the sum of the digits each domino cage.  For example, suppose the green domino (upper left) contains the digits 6 & 4.  The sum is 10.  The sum of the cells in the yellow domino (upper right) can be either 5 or 15 since the black rectangle connecting them has a 5 inside. 

The entire puzzle is shown below. 

Rules

Normal Sudoku Rules Apply.
The box centers (light blue) form a magic square.
The thermometer increases from the bulb to the end.
Domino cages can not be repeated. For example, a cage with 5&6 precludes 5&6 from being used in any other cage.
The digits in the black rectangles show the difference between the sums of the connected cages.

If you try this puzzle please let me know what you think on the ctc discord server or directly by email at “sudoku@elgrandpaduro.com“.

I expect the puzzle to be difficult especially considering the limited notation available on apps I have seen.  Starting with pencil and paper is probably easier at first.