At 42 grammes - height 55mm Width 22mm Im thinking of placing it aft under the battery will it have any effect on the drone stabilization or any other issues
if it is light the spark will have no trouble with self stabilisation as it is made to lift prop guards and other accesories which will be as heavy as that.
If it is heavy than good luck with getting your spark off the ground.
At 42 grammes - height 55mm Width 22mm Im thinking of placing it aft under the battery will it have any effect on the drone stabilization or any other issues
The spark will barely know it is there. Folks add trackers, strobes, legs, filters, guards and more. It can basically lift it's own weight (as proven by others).