Do you want the ball to go in the hole or not? ;) Lol
You stick with the 1st calculation.
The only thing I might do after aiming and the elevation changes is..
- hit the ball a bit harder for uphill
- give a bit more break for downhill
- could also mis-ding a bit into the break
Because the ball has to travel through that elevation change, but I wouldn't adjust very much unless the elevation changes were severe.
Another thing is be careful with what the game is saying for elevation -- sometimes it lies.
For uphill putts note what the game initially shows for elevation.
Switch to reverse view and move the aimer from the centre of the cup to the back of the cup and about a cup's width beyond. You might notice the elevation change. If it does, those are the numbers you want to use to calculate your break.
This is because the game only reports whole numbers. That putt might actually be 2.85" uphill and the only way to know that is to check, but the game won't report 3", it'll report 2.
HTH and good luck!