Originally Posted by
FBinNY
If anything you made the steerer stronger by moving the stem lower. If the steerer were to break, it's far more likely with the stem at the top, farther away from the support of the headset.
It's the same with seat posts. All things being equal the longer the exposed post, the more likely it is to break.
+1 You did indeed reduce the stress on the steerer. BTW. there is a maximum spacer stack generally recommended by carbon fork makers, 25 mm for a 1" steerer and 40 - 50 mm for a 1-1/8" steerer. What is the spacer stack height when your stem is all the way up?